bcm4908: initial work on the Broadcom BCM4908 target

BCM4906, BCM4908 and BCM49408 are SoCs with 64 bit ARMv8 B53 CPUs.
Upstream Linux is slowly getting support for that SoCs family so it
makes sense to add target for it.

This prepares initial support for:

1. Asus GT-AC5300
BCM4908 based device (4 CPUs) with 1024 MiB RAM, NAND, 8 LAN ports.

2. Netgear R8000P
BCM4906 based device (2 CPUs) with 512 MiB RAM, NAND, 4 LAN ports.

Flashing info will come later as we learn how to generate proper images.

It isn't usable yet (it only produces a bootable kernel) so "source-only"
is used.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

7 files changed, 623 insertions, 0 deletions

diff --git a/target/linux/bcm4908/Makefile b/target/linux/bcm4908/Makefile
new file mode 100644
index 0000000000..d5f82a188e
--- /dev/null
+++ b/target/linux/bcm4908/Makefile
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+include $(TOPDIR)/rules.mk
+
+ARCH:=aarch64
+BOARD:=bcm4908
+BOARDNAME:=Broadcom BCM4908 (ARMv8A CPUs Brahma-B53)
+FEATURES:=squashfs nand usb pci pcie gpio source-only
+CPU_TYPE:=cortex-a53
+SUBTARGETS:=generic
+
+KERNEL_PATCHVER:=5.4
+KERNEL_TESTING_PATCHVER:=5.4
+
+define Target/Description
+	Build firmware images for Broadcom BCM4908 SoC family routers.
+endef
+
+include $(INCLUDE_DIR)/target.mk
+
+KERNELNAME:=Image dtbs
+
+$(eval $(call BuildTarget))
diff --git a/target/linux/bcm4908/config-5.4 b/target/linux/bcm4908/config-5.4
new file mode 100644
index 0000000000..df20191ac8
--- /dev/null
+++ b/target/linux/bcm4908/config-5.4
@@ -0,0 +1,178 @@
+CONFIG_64BIT=y
+CONFIG_ARCH_BCM4908=y
+CONFIG_ARCH_CLOCKSOURCE_DATA=y
+CONFIG_ARCH_DMA_ADDR_T_64BIT=y
+CONFIG_ARCH_KEEP_MEMBLOCK=y
+CONFIG_ARCH_MMAP_RND_BITS=18
+CONFIG_ARCH_MMAP_RND_BITS_MAX=24
+CONFIG_ARCH_MMAP_RND_BITS_MIN=18
+CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MIN=11
+CONFIG_ARCH_PROC_KCORE_TEXT=y
+CONFIG_ARCH_SELECT_MEMORY_MODEL=y
+CONFIG_ARCH_SPARSEMEM_DEFAULT=y
+CONFIG_ARCH_SPARSEMEM_ENABLE=y
+CONFIG_ARCH_SUSPEND_POSSIBLE=y
+CONFIG_ARM64=y
+CONFIG_ARM64_4K_PAGES=y
+CONFIG_ARM64_CONT_SHIFT=4
+CONFIG_ARM64_ERRATUM_1165522=y
+CONFIG_ARM64_ERRATUM_1286807=y
+CONFIG_ARM64_PAGE_SHIFT=12
+CONFIG_ARM64_PA_BITS=48
+CONFIG_ARM64_PA_BITS_48=y
+CONFIG_ARM64_PTR_AUTH=y
+CONFIG_ARM64_SSBD=y
+CONFIG_ARM64_SVE=y
+CONFIG_ARM64_TAGGED_ADDR_ABI=y
+CONFIG_ARM64_VA_BITS=39
+CONFIG_ARM64_VA_BITS_39=y
+CONFIG_ARM64_WORKAROUND_REPEAT_TLBI=y
+CONFIG_ARM_AMBA=y
+CONFIG_ARM_ARCH_TIMER=y
+CONFIG_ARM_ARCH_TIMER_EVTSTREAM=y
+CONFIG_ARM_GIC=y
+CONFIG_ARM_GIC_V3=y
+CONFIG_ARM_GIC_V3_ITS=y
+CONFIG_ARM_PSCI_FW=y
+CONFIG_AUDIT_ARCH_COMPAT_GENERIC=y
+CONFIG_BCM7XXX_PHY=y
+CONFIG_BCM_NET_PHYLIB=y
+# CONFIG_BLK_DEV_INITRD is not set
+CONFIG_CAVIUM_TX2_ERRATUM_219=y
+CONFIG_CLKDEV_LOOKUP=y
+CONFIG_CLONE_BACKWARDS=y
+CONFIG_CMDLINE="earlycon=bcm63xx_uart,0xff800640"
+CONFIG_CMDLINE_FORCE=y
+CONFIG_COMMON_CLK=y
+CONFIG_CPU_RMAP=y
+CONFIG_CRYPTO_AEAD=y
+CONFIG_CRYPTO_AEAD2=y
+CONFIG_CRYPTO_HASH2=y
+CONFIG_CRYPTO_MANAGER=y
+CONFIG_CRYPTO_MANAGER2=y
+CONFIG_CRYPTO_NULL2=y
+CONFIG_CRYPTO_RNG2=y
+CONFIG_DCACHE_WORD_ACCESS=y
+CONFIG_DMA_DIRECT_REMAP=y
+CONFIG_DMA_REMAP=y
+CONFIG_DRM_RCAR_WRITEBACK=y
+CONFIG_DTC=y
+CONFIG_EDAC_SUPPORT=y
+CONFIG_FIXED_PHY=y
+CONFIG_FIX_EARLYCON_MEM=y
+CONFIG_FRAME_POINTER=y
+CONFIG_FUJITSU_ERRATUM_010001=y
+CONFIG_FW_LOADER_PAGED_BUF=y
+CONFIG_GENERIC_ALLOCATOR=y
+CONFIG_GENERIC_ARCH_TOPOLOGY=y
+CONFIG_GENERIC_BUG=y
+CONFIG_GENERIC_BUG_RELATIVE_POINTERS=y
+CONFIG_GENERIC_CLOCKEVENTS=y
+CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y
+CONFIG_GENERIC_CPU_AUTOPROBE=y
+CONFIG_GENERIC_CPU_VULNERABILITIES=y
+CONFIG_GENERIC_CSUM=y
+CONFIG_GENERIC_EARLY_IOREMAP=y
+CONFIG_GENERIC_GETTIMEOFDAY=y
+CONFIG_GENERIC_IDLE_POLL_SETUP=y
+CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK=y
+CONFIG_GENERIC_IRQ_MULTI_HANDLER=y
+CONFIG_GENERIC_IRQ_SHOW=y
+CONFIG_GENERIC_IRQ_SHOW_LEVEL=y
+CONFIG_GENERIC_MSI_IRQ=y
+CONFIG_GENERIC_MSI_IRQ_DOMAIN=y
+CONFIG_GENERIC_PCI_IOMAP=y
+CONFIG_GENERIC_SCHED_CLOCK=y
+CONFIG_GENERIC_SMP_IDLE_THREAD=y
+CONFIG_GENERIC_STRNCPY_FROM_USER=y
+CONFIG_GENERIC_STRNLEN_USER=y
+CONFIG_GENERIC_TIME_VSYSCALL=y
+CONFIG_GPIOLIB=y
+CONFIG_GPIO_GENERIC=y
+CONFIG_GPIO_GENERIC_PLATFORM=y
+CONFIG_HANDLE_DOMAIN_IRQ=y
+CONFIG_HARDEN_BRANCH_PREDICTOR=y
+CONFIG_HARDIRQS_SW_RESEND=y
+CONFIG_HAS_DMA=y
+CONFIG_HAS_IOMEM=y
+CONFIG_HOLES_IN_ZONE=y
+CONFIG_HZ=250
+CONFIG_HZ_250=y
+CONFIG_HZ_PERIODIC=y
+CONFIG_ILLEGAL_POINTER_VALUE=0xdead000000000000
+CONFIG_IRQCHIP=y
+CONFIG_IRQ_DOMAIN=y
+CONFIG_IRQ_DOMAIN_HIERARCHY=y
+CONFIG_IRQ_FORCED_THREADING=y
+CONFIG_IRQ_WORK=y
+CONFIG_LEDS_GPIO=y
+CONFIG_LIBFDT=y
+CONFIG_LOCK_DEBUGGING_SUPPORT=y
+CONFIG_LOCK_SPIN_ON_OWNER=y
+CONFIG_MDIO_BCM_UNIMAC=y
+CONFIG_MDIO_BUS=y
+CONFIG_MDIO_DEVICE=y
+CONFIG_MEMFD_CREATE=y
+CONFIG_MFD_SYSCON=y
+CONFIG_MIGRATION=y
+CONFIG_MODULES_USE_ELF_RELA=y
+CONFIG_MTD_NAND_BRCMNAND=y
+CONFIG_MTD_NAND_CORE=y
+CONFIG_MTD_NAND_ECC_SW_HAMMING=y
+CONFIG_MTD_RAW_NAND=y
+CONFIG_MUTEX_SPIN_ON_OWNER=y
+CONFIG_NEED_DMA_MAP_STATE=y
+CONFIG_NEED_SG_DMA_LENGTH=y
+CONFIG_NET_FLOW_LIMIT=y
+CONFIG_NO_IOPORT_MAP=y
+CONFIG_NR_CPUS=4
+CONFIG_OF=y
+CONFIG_OF_ADDRESS=y
+CONFIG_OF_EARLY_FLATTREE=y
+CONFIG_OF_FLATTREE=y
+CONFIG_OF_GPIO=y
+CONFIG_OF_IRQ=y
+CONFIG_OF_KOBJ=y
+CONFIG_OF_MDIO=y
+CONFIG_OF_NET=y
+CONFIG_PADATA=y
+CONFIG_PARTITION_PERCPU=y
+CONFIG_PGTABLE_LEVELS=3
+CONFIG_PHYLIB=y
+CONFIG_PHYS_ADDR_T_64BIT=y
+CONFIG_POWER_RESET=y
+CONFIG_POWER_RESET_SYSCON=y
+CONFIG_POWER_SUPPLY=y
+CONFIG_QUEUED_RWLOCKS=y
+CONFIG_QUEUED_SPINLOCKS=y
+CONFIG_RATIONAL=y
+CONFIG_RCU_NEED_SEGCBLIST=y
+CONFIG_RCU_STALL_COMMON=y
+CONFIG_REFCOUNT_FULL=y
+CONFIG_REGMAP=y
+CONFIG_REGMAP_MMIO=y
+CONFIG_RFS_ACCEL=y
+CONFIG_RODATA_FULL_DEFAULT_ENABLED=y
+CONFIG_RPS=y
+CONFIG_RWSEM_SPIN_ON_OWNER=y
+# CONFIG_SERIAL_8250 is not set
+CONFIG_SERIAL_BCM63XX=y
+CONFIG_SERIAL_BCM63XX_CONSOLE=y
+CONFIG_SMP=y
+CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y
+CONFIG_SPARSE_IRQ=y
+CONFIG_SRCU=y
+CONFIG_SWIOTLB=y
+CONFIG_SWPHY=y
+CONFIG_SYSCTL_EXCEPTION_TRACE=y
+CONFIG_SYS_SUPPORTS_HUGETLBFS=y
+CONFIG_THREAD_INFO_IN_TASK=y
+CONFIG_TICK_CPU_ACCOUNTING=y
+CONFIG_TIMER_OF=y
+CONFIG_TIMER_PROBE=y
+CONFIG_TREE_RCU=y
+CONFIG_TREE_SRCU=y
+CONFIG_UNMAP_KERNEL_AT_EL0=y
+CONFIG_VMAP_STACK=y
+CONFIG_XPS=y
+CONFIG_ZONE_DMA32=y
diff --git a/target/linux/bcm4908/generic/target.mk b/target/linux/bcm4908/generic/target.mk
new file mode 100644
index 0000000000..f5cb1fb19b
--- /dev/null
+++ b/target/linux/bcm4908/generic/target.mk
@@ -0,0 +1 @@
+BOARDNAME:=Generic
diff --git a/target/linux/bcm4908/image/Makefile b/target/linux/bcm4908/image/Makefile
new file mode 100644
index 0000000000..7eaafd583c
--- /dev/null
+++ b/target/linux/bcm4908/image/Makefile
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/image.mk
+
+define Build/bcm4908lzma
+	$(STAGING_DIR_HOST)/bin/lzma e -lc1 -lp2 -pb2 -d22 $@ $@.new
+	mv $@.new $@
+endef
+
+define Device/Default
+  KERNEL := kernel-bin | bcm4908lzma
+  KERNEL_DEPENDS = $$(wildcard $(DTS_DIR)/$$(DEVICE_DTS).dts)
+  KERNEL_INITRAMFS_SUFFIX := .bin
+  KERNEL_INITRAMFS := kernel-bin | bcm4908lzma
+  FILESYSTEMS := squashfs
+  KERNEL_NAME := Image
+  IMAGE_NAME = $$(IMAGE_PREFIX)-$$(1).$$(2)
+  BLOCKSIZE := 128k
+  PAGESIZE := 2048
+endef
+
+define Device/asus_gt-ac5300
+  DEVICE_VENDOR := Asus
+  DEVICE_MODEL := GT-AC5300
+  DEVICE_DTS := broadcom/bcm4908/bcm4908-asus-gt-ac5300
+  IMAGES := bin
+endef
+TARGET_DEVICES += asus_gt-ac5300
+
+define Device/netgear_r8000p
+  DEVICE_VENDOR := Netgear
+  DEVICE_MODEL := R8000P
+  DEVICE_DTS := broadcom/bcm4908/bcm4906-netgear-r8000p
+  IMAGES := bin
+endef
+TARGET_DEVICES += netgear_r8000p
+
+$(eval $(call BuildImage))
diff --git a/target/linux/bcm4908/patches-5.4/030-v5.11-0001-arm64-dts-broadcom-add-BCM4908-and-Asus-GT-AC5300-ea.patch b/target/linux/bcm4908/patches-5.4/030-v5.11-0001-arm64-dts-broadcom-add-BCM4908-and-Asus-GT-AC5300-ea.patch
new file mode 100644
index 0000000000..3598b5b9c7
--- /dev/null
+++ b/target/linux/bcm4908/patches-5.4/030-v5.11-0001-arm64-dts-broadcom-add-BCM4908-and-Asus-GT-AC5300-ea.patch
@@ -0,0 +1,307 @@
+From 2961f69f151c0a6771f55cef46398fe49ca20902 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Thu, 12 Nov 2020 16:08:32 +0100
+Subject: [PATCH] arm64: dts: broadcom: add BCM4908 and Asus GT-AC5300 early
+ DTS files
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+They don't descibe hardware fully yet but it's enough to boot a system.
+
+Some missing blocks:
+1. PMC (Power Management Controller?)
+2. Ethernet
+3. Crypto
+4. Thermal
+
+Asus DTS is missing defining full NAND partitions layout and buttons.
+
+Further changes will fill those gaps as soon as required bindings will
+be found / tested / added.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
+---
+ arch/arm64/boot/dts/broadcom/Makefile         |   1 +
+ arch/arm64/boot/dts/broadcom/bcm4908/Makefile |   2 +
+ .../bcm4908/bcm4908-asus-gt-ac5300.dts        |  66 +++++++
+ .../boot/dts/broadcom/bcm4908/bcm4908.dtsi    | 187 ++++++++++++++++++
+ 4 files changed, 256 insertions(+)
+ create mode 100644 arch/arm64/boot/dts/broadcom/bcm4908/Makefile
+ create mode 100644 arch/arm64/boot/dts/broadcom/bcm4908/bcm4908-asus-gt-ac5300.dts
+ create mode 100644 arch/arm64/boot/dts/broadcom/bcm4908/bcm4908.dtsi
+
+--- a/arch/arm64/boot/dts/broadcom/Makefile
++++ b/arch/arm64/boot/dts/broadcom/Makefile
+@@ -4,5 +4,6 @@ dtb-$(CONFIG_ARCH_BCM2835) += bcm2837-rp
+ 			      bcm2837-rpi-3-b-plus.dtb \
+ 			      bcm2837-rpi-cm3-io3.dtb
+ 
++subdir-y	+= bcm4908
+ subdir-y	+= northstar2
+ subdir-y	+= stingray
+--- /dev/null
++++ b/arch/arm64/boot/dts/broadcom/bcm4908/Makefile
+@@ -0,0 +1,2 @@
++# SPDX-License-Identifier: GPL-2.0
++dtb-$(CONFIG_ARCH_BCM4908) += bcm4908-asus-gt-ac5300.dtb
+--- /dev/null
++++ b/arch/arm64/boot/dts/broadcom/bcm4908/bcm4908-asus-gt-ac5300.dts
+@@ -0,0 +1,66 @@
++// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
++
++#include <dt-bindings/gpio/gpio.h>
++#include <dt-bindings/input/input.h>
++
++#include "bcm4908.dtsi"
++
++/ {
++	compatible = "asus,gt-ac5300", "brcm,bcm4908";
++	model = "Asus GT-AC5300";
++
++	memory@0 {
++		device_type = "memory";
++		reg = <0x00 0x00 0x00 0x40000000>;
++	};
++
++	gpio-keys-polled {
++		compatible = "gpio-keys-polled";
++		poll-interval = <100>;
++
++		wifi {
++			label = "WiFi";
++			linux,code = <KEY_RFKILL>;
++			gpios = <&gpio0 28 GPIO_ACTIVE_LOW>;
++		};
++
++		wps {
++			label = "WPS";
++			linux,code = <KEY_WPS_BUTTON>;
++			gpios = <&gpio0 29 GPIO_ACTIVE_LOW>;
++		};
++
++		restart {
++			label = "Reset";
++			linux,code = <KEY_RESTART>;
++			gpios = <&gpio0 30 GPIO_ACTIVE_LOW>;
++		};
++
++		brightness {
++			label = "LEDs";
++			linux,code = <KEY_BRIGHTNESS_ZERO>;
++			gpios = <&gpio0 31 GPIO_ACTIVE_LOW>;
++		};
++	};
++};
++
++&nandcs {
++	nand-ecc-strength = <4>;
++	nand-ecc-step-size = <512>;
++	nand-on-flash-bbt;
++	brcm,nand-has-wp;
++
++	#address-cells = <1>;
++	#size-cells = <0>;
++
++	partitions {
++		compatible = "fixed-partitions";
++		#address-cells = <1>;
++		#size-cells = <1>;
++
++		partition@0 {
++			label = "cferom";
++			reg = <0x0 0x100000>;
++		};
++	};
++};
+--- /dev/null
++++ b/arch/arm64/boot/dts/broadcom/bcm4908/bcm4908.dtsi
+@@ -0,0 +1,187 @@
++// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
++
++#include <dt-bindings/interrupt-controller/irq.h>
++#include <dt-bindings/interrupt-controller/arm-gic.h>
++
++/dts-v1/;
++
++/ {
++	interrupt-parent = <&gic>;
++
++	#address-cells = <2>;
++	#size-cells = <2>;
++
++	aliases {
++		serial0 = &uart0;
++	};
++
++	chosen {
++		stdout-path = "serial0:115200n8";
++	};
++
++	cpus {
++		#address-cells = <1>;
++		#size-cells = <0>;
++
++		cpu0: cpu@0 {
++			device_type = "cpu";
++			compatible = "brcm,brahma-b53";
++			reg = <0x0>;
++			next-level-cache = <&l2>;
++		};
++
++		cpu1: cpu@1 {
++			device_type = "cpu";
++			compatible = "brcm,brahma-b53";
++			reg = <0x1>;
++			enable-method = "spin-table";
++			cpu-release-addr = <0x0 0xfff8>;
++			next-level-cache = <&l2>;
++		};
++
++		cpu2: cpu@2 {
++			device_type = "cpu";
++			compatible = "brcm,brahma-b53";
++			reg = <0x2>;
++			enable-method = "spin-table";
++			cpu-release-addr = <0x0 0xfff8>;
++			next-level-cache = <&l2>;
++		};
++
++		cpu3: cpu@3 {
++			device_type = "cpu";
++			compatible = "brcm,brahma-b53";
++			reg = <0x3>;
++			enable-method = "spin-table";
++			cpu-release-addr = <0x0 0xfff8>;
++			next-level-cache = <&l2>;
++		};
++
++		l2: l2-cache0 {
++			compatible = "cache";
++		};
++	};
++
++	axi@81000000 {
++		compatible = "simple-bus";
++		#address-cells = <1>;
++		#size-cells = <1>;
++		ranges = <0x00 0x00 0x81000000 0x4000>;
++
++		gic: interrupt-controller@1000 {
++			compatible = "arm,gic-400";
++			#interrupt-cells = <3>;
++			#address-cells = <0>;
++			interrupt-controller;
++			reg = <0x1000 0x1000>,
++			      <0x2000 0x2000>;
++		};
++	};
++
++	timer {
++		compatible = "arm,armv8-timer";
++		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
++			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
++			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
++			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;
++	};
++
++	pmu {
++		compatible = "arm,cortex-a53-pmu";
++		interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>,
++			     <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>,
++			     <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>,
++			     <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
++		interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
++	};
++
++	clocks {
++		periph_clk: periph_clk {
++			compatible = "fixed-clock";
++			#clock-cells = <0>;
++			clock-frequency = <50000000>;
++			clock-output-names = "periph";
++		};
++	};
++
++	soc {
++		compatible = "simple-bus";
++		#address-cells = <1>;
++		#size-cells = <1>;
++		ranges = <0x00 0x00 0x80000000 0x10000>;
++
++		usb@c300 {
++			compatible = "generic-ehci";
++			reg = <0xc300 0x100>;
++			interrupts = <GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>;
++			status = "disabled";
++		};
++
++		usb@c400 {
++			compatible = "generic-ohci";
++			reg = <0xc400 0x100>;
++			interrupts = <GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH>;
++			status = "disabled";
++		};
++
++		usb@d000 {
++			compatible = "generic-xhci";
++			reg = <0xd000 0x8c8>;
++			interrupts = <GIC_SPI 74 IRQ_TYPE_LEVEL_HIGH>;
++			status = "disabled";
++		};
++	};
++
++	bus@ff800000 {
++		compatible = "simple-bus";
++		#address-cells = <1>;
++		#size-cells = <1>;
++		ranges = <0x00 0x00 0xff800000 0x3000>;
++
++		timer: timer@400 {
++			compatible = "brcm,bcm6328-timer", "syscon";
++			reg = <0x400 0x3c>;
++		};
++
++		gpio0: gpio-controller@500 {
++			compatible = "brcm,bcm6345-gpio";
++			reg-names = "dirout", "dat";
++			reg = <0x500 0x28>, <0x528 0x28>;
++
++			#gpio-cells = <2>;
++			gpio-controller;
++		};
++
++		uart0: serial@640 {
++			compatible = "brcm,bcm6345-uart";
++			reg = <0x640 0x18>;
++			interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
++			clocks = <&periph_clk>;
++			clock-names = "periph";
++			status = "okay";
++		};
++
++		nand@1800 {
++			#address-cells = <1>;
++			#size-cells = <0>;
++			compatible = "brcm,brcmnand-v7.1", "brcm,brcmnand";
++			reg = <0x1800 0x600>, <0x2000 0x10>;
++			reg-names = "nand", "nand-int-base";
++			interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
++			interrupt-names = "nand";
++			status = "okay";
++
++			nandcs: nandcs@0 {
++				compatible = "brcm,nandcs";
++				reg = <0>;
++			};
++		};
++
++		reboot {
++			compatible = "syscon-reboot";
++			regmap = <&timer>;
++			offset = <0x34>;
++			mask = <1>;
++		};
++	};
++};
diff --git a/target/linux/bcm4908/patches-5.4/030-v5.11-0002-v5.11-arm64-add-config-for-Broadcom-BCM4908-SoCs.patch b/target/linux/bcm4908/patches-5.4/030-v5.11-0002-v5.11-arm64-add-config-for-Broadcom-BCM4908-SoCs.patch
new file mode 100644
index 0000000000..42bdbf51b6
--- /dev/null
+++ b/target/linux/bcm4908/patches-5.4/030-v5.11-0002-v5.11-arm64-add-config-for-Broadcom-BCM4908-SoCs.patch
@@ -0,0 +1,44 @@
+From dccb22d078ebd098115e4f66bde1ee2249c8640b Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Thu, 12 Nov 2020 16:08:30 +0100
+Subject: [PATCH] arm64: add config for Broadcom BCM4908 SoCs
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Add ARCH_BCM4908 config that can be used for compiling DTS files.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
+---
+ arch/arm64/Kconfig.platforms | 8 ++++++++
+ arch/arm64/configs/defconfig | 1 +
+ 2 files changed, 9 insertions(+)
+
+--- a/arch/arm64/Kconfig.platforms
++++ b/arch/arm64/Kconfig.platforms
+@@ -43,6 +43,14 @@ config ARCH_BCM2835
+ 	  This enables support for the Broadcom BCM2837 SoC.
+ 	  This SoC is used in the Raspberry Pi 3 device.
+ 
++config ARCH_BCM4908
++	bool "Broadcom BCM4908 family"
++	select GPIOLIB
++	help
++	  This enables support for the Broadcom BCM4906, BCM4908 and
++	  BCM49408 SoCs. These SoCs use Brahma-B53 cores and can be
++	  found in home routers.
++
+ config ARCH_BCM_IPROC
+ 	bool "Broadcom iProc SoC Family"
+ 	select COMMON_CLK_IPROC
+--- a/arch/arm64/configs/defconfig
++++ b/arch/arm64/configs/defconfig
+@@ -33,6 +33,7 @@ CONFIG_ARCH_AGILEX=y
+ CONFIG_ARCH_SUNXI=y
+ CONFIG_ARCH_ALPINE=y
+ CONFIG_ARCH_BCM2835=y
++CONFIG_ARCH_BCM4908=y
+ CONFIG_ARCH_BCM_IPROC=y
+ CONFIG_ARCH_BERLIN=y
+ CONFIG_ARCH_BRCMSTB=y
diff --git a/target/linux/bcm4908/patches-5.4/080-v5.11-tty-serial-bcm63xx-lower-driver-dependencies.patch b/target/linux/bcm4908/patches-5.4/080-v5.11-tty-serial-bcm63xx-lower-driver-dependencies.patch
new file mode 100644
index 0000000000..8da2fe8cf2
--- /dev/null
+++ b/target/linux/bcm4908/patches-5.4/080-v5.11-tty-serial-bcm63xx-lower-driver-dependencies.patch
@@ -0,0 +1,31 @@
+From f35a07f92616700733636c06dd6e5b6cdc807fe4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Wed, 25 Nov 2020 10:06:08 +0100
+Subject: [PATCH] tty: serial: bcm63xx: lower driver dependencies
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Hardware supported by bcm63xx is also used by BCM4908 SoCs family that
+is ARM64. In future more architectures may need it as well. There is
+nothing arch specific breaking compilation so just stick to requiring
+COMMON_CLK.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Link: https://lore.kernel.org/r/20201125090608.28442-1-zajec5@gmail.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/serial/Kconfig | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/tty/serial/Kconfig
++++ b/drivers/tty/serial/Kconfig
+@@ -1125,7 +1125,7 @@ config SERIAL_TIMBERDALE
+ config SERIAL_BCM63XX
+ 	tristate "Broadcom BCM63xx/BCM33xx UART support"
+ 	select SERIAL_CORE
+-	depends on MIPS || ARM || COMPILE_TEST
++	depends on COMMON_CLK
+ 	help
+ 	  This enables the driver for the onchip UART core found on
+ 	  the following chipsets: