ramips: add support for Edimax RG21S

SoC:	MediaTek MT7621AT dual-core @ 880MHz
RAM:	256M (Nanya NT5CC128M)
FLASH:	16MB (Macronix MX25L12835F)
WiFi:	- 2.4GHz MediaTek MT7615N bgn
	- 5GHz MediaTek MT7615N nac
Switch: SoC integrated Gigabit Switch (4 x LAN, 1 x WAN)
USB:	No
BTN:	Reset, WPS
LED:	4 red LEDs, indistinguishable when casing closed
UART: 	UART is present as Pads marked J1 on the PCB.
	3.3V - RX - GND - TX / 57600-8N1
	3.3V is the square pad

Installation
------------
Update the factory image via the OEM web-interface
(by default:http://192.168.1.1)
The sysupgrade image can be installed via TFTP from
the U-Boot bootloader. Connect ethernet port 2.

Signed-off-by: Birger Koblitz <mail@birger-koblitz.de>
[flash node rename, EDIMAX -> Edimax, complete device model name]
Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/ramips/base-files/etc/board.d/02_network

@@ -333,6 +333,10 @@ ramips_setup_interfaces()
 		ucidef_add_switch "switch0" \
 			"0:lan" "4:wan" "6@eth0"
 		;;
+	edimax,rg21s)
+		ucidef_add_switch "switch0" \
+			"1:lan:4" "2:lan:3" "3:lan:2" "4:lan:1" "0:wan" "6@eth0"
+		;;
 	gehua,ghl-r-001)
 		ucidef_add_switch "switch0" \
 			"0:lan" "1:lan" "2:lan" "4:wan" "6@eth0"
@@ -624,6 +628,10 @@ ramips_setup_macs()
 	netgear,r6850)
 		wan_mac=$(macaddr_add "$(cat /sys/class/net/eth0/address)" 2)
 		;;
+	edimax,rg21s)
+		lan_mac=$(mtd_get_mac_ascii u-boot-env ethaddr)
+		wan_mac=$(mtd_get_mac_ascii u-boot-env wanaddr)
+		;;
 	hiwifi,hc5661|\
 	hiwifi,hc5661a|\
 	hiwifi,hc5761|\

target/linux/ramips/dts/mt7621_edimax_rg21s.dts

@@ -0,0 +1,155 @@
+// 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>
+
+/ {
+	compatible = "edimax,rg21s", "mediatek,mt7621-soc";
+	model = "Edimax RG21S";
+
+	aliases {
+		led-boot = &led_power;
+		led-failsafe = &led_power;
+		led-running = &led_power;
+		led-upgrade = &led_power;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,57600";
+	};
+
+	palmbus: palmbus@1E000000 {
+		i2c@900 {
+			status = "okay";
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio0 16 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		wps {
+			label = "wps";
+			gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_power: led_1 {
+			label = "rg21s:red:led1";
+			gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>;
+		};
+
+		led_2 {
+			label = "rg21s:red:led2";
+			gpios = <&gpio0 12 GPIO_ACTIVE_HIGH>;
+		};
+
+		led_3 {
+			label = "rg21s:red:led3";
+			gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
+		};
+
+		led_4 {
+			label = "rg21s:red:led4";
+			gpios = <&gpio0 15 GPIO_ACTIVE_HIGH>;
+		};
+	};
+};
+
+&sdhci {
+	status = "okay";
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <10000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x0 0x30000>;
+				read-only;
+			};
+
+			partition@30000 {
+				label = "u-boot-env";
+				reg = <0x30000 0x10000>;
+				read-only;
+			};
+
+			factory: partition@40000 {
+				label = "factory";
+				reg = <0x40000 0x10000>;
+				read-only;
+			};
+
+			partition@50000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x50000 0xfb0000>;
+			};
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi0: wifi@0,0 {
+		compatible = "pci14c3,7615";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&factory 0x0000>;
+		ieee80211-freq-limit = <2400000 2500000>;
+	};
+};
+
+&pcie1 {
+	wifi1: wifi@0,0 {
+		compatible = "pci14c3,7615";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&factory 0x8000>;
+		ieee80211-freq-limit = <5000000 6000000>;
+	};
+};
+
+&ethernet {
+	mediatek,portmap = "wllll";
+	port@5 {
+		status = "disabled";
+	};
+};
+
+&pinctrl {
+	state_default: pinctrl0 {
+		gpio {
+			ralink,group = "wdt", "rgmii2", "jtag", "mdio";
+			ralink,function = "gpio";
+		};
+	};
+};
+
+&xhci {
+	status = "disabled";
+};

target/linux/ramips/image/mt7621.mk

@@ -30,6 +30,25 @@ define Build/elecom-wrc-factory
   mv $@.new $@
 endef
 
+define Build/elx-header
+  $(eval hw_id=$(word 1,$(1)))
+  $(eval xor_pattern=$(word 2,$(1)))
+  ( \
+    echo -ne "\x00\x00\x00\x00\x00\x00\x00\x03" | \
+      dd bs=42 count=1 conv=sync; \
+    hw_id="$(hw_id)"; \
+    echo -ne "\x$${hw_id:0:2}\x$${hw_id:2:2}\x$${hw_id:4:2}\x$${hw_id:6:2}" | \
+      dd bs=20 count=1 conv=sync; \
+    echo -ne "$$(printf '%08x' $$(stat -c%s $@) | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
+      dd bs=8 count=1 conv=sync; \
+    echo -ne "$$($(STAGING_DIR_HOST)/bin/mkhash md5 $@ | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
+      dd bs=58 count=1 conv=sync; \
+  ) > $(KDIR)/tmp/$(DEVICE_NAME).header
+  $(call Build/xor-image,-p $(xor_pattern) -x)
+  cat $(KDIR)/tmp/$(DEVICE_NAME).header $@ > $@.new
+  mv $@.new $@
+endef
+
 define Build/iodata-factory
   $(eval fw_size=$(word 1,$(1)))
   $(eval fw_type=$(word 2,$(1)))
@@ -173,6 +192,20 @@ define Device/d-team_pbr-m1
 endef
 TARGET_DEVICES += d-team_pbr-m1
 
+define Device/edimax_rg21s
+  MTK_SOC := mt7621
+  IMAGE_SIZE := 16064k
+  DEVICE_VENDOR := Edimax
+  DEVICE_MODEL := Gemini AC2600 RG21S
+  IMAGES += factory.bin
+  IMAGE/factory.bin := \
+    $$(sysupgrade_bin) | check-size $$$$(IMAGE_SIZE) | \
+    elx-header 02020038 8844A2D168B45A2D
+  DEVICE_PACKAGES := \
+        kmod-mt7615e wpad-basic
+endef
+TARGET_DEVICES += edimax_rg21s
+
 define Device/elecom_wrc-1167ghbk2-s
   MTK_SOC := mt7621
   IMAGE_SIZE := 15488k