ramips: Add support for Xiaomi Mi Router(Black,R2100)

The Xiaomi Mi Router AC2100 is a *black* cylindrical router that shares many
characteristics (apart from its looks and the GPIO ports) with the 6-antenna
*white* "Xiaomi Redmi Router AC2100"

See the visual comparison of the two routers here:
https://github.com/emirefek/openwrt-R2100/raw/imgcdn/rm2100-r2100.jpg

Specification of R2100:
- CPU: MediaTek MT7621A
- RAM: 128 MB DDR3
- FLASH: 128 MB ESMT NAND
- WIFI: 2x2 802.11bgn (MT7603)
- WIFI: 4x4 802.11ac (MT7615)
- ETH: 3xLAN+1xWAN 1000base-T
- LED: Power, WAN in Yellow and Blue
- UART: On board (Don't know where is should be confirmed by anybody else)
- Modified u-boot

Hacking of official firmware process is same at both RM2100 and R2100.
Thanks to @namidairo

Here is the detailed guide Hack: https://github.com/impulse/ac2100-openwrt-guide
Guide is written for MacOS but it will work at linux.
needed packages: python3(with scapy), netcat, http server, telnet client

1. Run PPPoE&exploit to get nc and wget busybox, get telnet and wget firmware
2. mtd write openwrt-ramips-mt7621-xiaomi_mi-router-ac2100-kernel1.bin kernel1
3. nvram set uart_en=1
4. nvram set bootdelay=5
5. nvram set flag_try_sys1_failed=1
6. nvram commit
7. mtd -r write openwrt-ramips-mt7621-xiaomi_mi-router-ac2100-rootfs0.bin rootfs0

other than these I specified in here. Everything is same with:
https://github.com/openwrt/openwrt/commit/f3792690c4f0567a8965d82898295b9d50c3bb7e
Thanks for all community and especially for this device:
@Ilyas @scp07 @namidairo @Percy @thorsten97 @impulse (names@forum.openwrt.com)

MAC Locations:
WAN *:b5 = factory 0xe006
LAN *:b6 = factory 0xe000
WIFI 5ghz *:b8 = factory 0x8004
WIFI 2.4ghz *:b7 = factory 0x0004

Signed-off-by: Emir Efe Kucuk <emirefek@gmail.com>
[refactored common image bits into Device/xiaomi-ac2100, fixed From:]
Signed-off-by: Petr Štetiar <ynezz@true.cz>

1 files changed, 1 insertions, 143 deletions

diff --git a/target/linux/ramips/dts/mt7621_xiaomi_redmi-router-ac2100.dts b/target/linux/ramips/dts/mt7621_xiaomi_redmi-router-ac2100.dts
index f0bc1aeb96..ceaeec750c 100644
--- a/target/linux/ramips/dts/mt7621_xiaomi_redmi-router-ac2100.dts
+++ b/target/linux/ramips/dts/mt7621_xiaomi_redmi-router-ac2100.dts
@@ -1,10 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later OR MIT
 /dts-v1/;
 
-#include "mt7621.dtsi"
-
-#include <dt-bindings/gpio/gpio.h>
-#include <dt-bindings/input/input.h>
+#include "mt7621_xiaomi_router-ac2100.dtsi"
 
 / {
 	compatible = "xiaomi,redmi-router-ac2100", "mediatek,mt7621-soc";
@@ -18,10 +15,6 @@
 		label-mac-device = &gmac0;
 	};
 
-	chosen {
-		bootargs = "console=ttyS0,115200n8";
-	};
-
 	leds {
 		compatible = "gpio-leds";
 
@@ -45,139 +38,4 @@
 			gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
 		};
 	};
-
-	keys {
-		compatible = "gpio-keys";
-
-		reset {
-			label = "reset";
-			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
-			linux,code = <KEY_RESTART>;
-		};
-	};
-
-};
-
-
-&nand {
-	status = "okay";
-
-	partitions {
-		compatible = "fixed-partitions";
-		#address-cells = <1>;
-		#size-cells = <1>;
-
-		partition@0 {
-			label = "Bootloader";
-			reg = <0x0 0x80000>;
-			read-only;
-		};
-
-		partition@80000 {
-			label = "Config";
-			reg = <0x80000 0x40000>;
-		};
-
-		partition@c0000 {
-			label = "Bdata";
-			reg = <0xc0000 0x40000>;
-			read-only;
-		};
-
-		factory: partition@100000 {
-			label = "factory";
-			reg = <0x100000 0x40000>;
-			read-only;
-		};
-
-		partition@140000 {
-			label = "crash";
-			reg = <0x140000 0x40000>;
-		};
-
-		partition@180000 {
-			label = "crash_syslog";
-			reg = <0x180000 0x40000>;
-		};
-
-		partition@1c0000 {
-			label = "reserved0";
-			reg = <0x1c0000 0x40000>;
-			read-only;
-		};
-
-		/* We keep stock xiaomi firmware (kernel0) here */
-		partition@200000 {
-			label = "kernel_stock";
-			reg = <0x200000 0x400000>;
-		};
-
-		partition@600000 {
-			label = "kernel";
-			reg = <0x600000 0x400000>;
-		};
-
-		partition@a00000 {
-			label = "ubi";
-			reg = <0xa00000 0x7580000>;
-		};
-	};
-};
-
-&pcie {
-	status = "okay";
-};
-
-&pcie0 {
-	wifi@0,0 {
-		compatible = "mediatek,mt76";
-		reg = <0x0000 0 0 0 0>;
-		mediatek,mtd-eeprom = <&factory 0x8000>;
-		ieee80211-freq-limit = <5000000 6000000>;
-	};
-};
-
-&pcie1 {
-	wifi@0,0 {
-		compatible = "mediatek,mt76";
-		reg = <0x0000 0 0 0 0>;
-		mediatek,mtd-eeprom = <&factory 0x0000>;
-		ieee80211-freq-limit = <2400000 2500000>;
-	};
-};
-
-&gmac0 {
-	mtd-mac-address = <&factory 0xe000>;
-};
-
-&switch0 {
-	ports {
-		port@0 {
-			status = "okay";
-			label = "wan";
-			mtd-mac-address = <&factory 0xe006>;
-		};
-
-		port@2 {
-			status = "okay";
-			label = "lan1";
-		};
-
-		port@3 {
-			status = "okay";
-			label = "lan2";
-		};
-
-		port@4 {
-			status = "okay";
-			label = "lan3";
-		};
-	};
-};
-
-&state_default {
-	gpio {
-		groups = "uart2", "uart3", "wdt";
-		function = "gpio";
-	};
 };