ramips: add support for TP-Link RE500 v1

This device uses the same hardware as RE650 v1 which got supported in
8c51dde.

Hardware specification:

- SoC 880 MHz - MediaTek MT7621AT
- 128 MB of DDR3 RAM
- 16 MB - Winbond 25Q128FVSG
- 4T4R 2.4 GHz - MediaTek MT7615E
- 4T4R 5 GHz - MediaTek MT7615E
- 1x 1 Gbps Ethernet - MT7621AT integrated
- 7x LEDs (Power, 2G, 5G, WPS(x2), Lan(x2))
- 4x buttons (Reset, Power, WPS, LED)
- UART header (J1) - 2:GND, 3:RX, 4:TX
  Serial console @ 57600,8n1

Flash instructions:

Upload
openwrt-ramips-mt7621-tplink_re500-v1-squashfs-factory.bin
from the RE500 web interface.

TFTP recovery to stock firmware:

Unfortunately, I can't find an easy way to recover the RE
without opening the device and using modified binaries. The
TFTP upload will only work if selected from u-boot, which
means you have to open the device and attach to the serial
console. The TFTP update procedure does *not* accept the
published vendor firmware binaries. However, it allows to
flash kernel + rootfs binaries, and this works if you have
a backup of the original contents of the flash. It's probably
possible to create special image out of the vendor binaries
and use that as recovery image.

Signed-off-by: Christoph Krapp <achterin@googlemail.com>
[remove dts-v1 in DTSI, do not touch WiFi LEDs for RE650, keep
state_default in DTS files, fix label-mac-device, use lower case
for WiFi LEDs]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

1 files changed, 131 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7621_tplink_rexx0-v1.dtsi b/target/linux/ramips/dts/mt7621_tplink_rexx0-v1.dtsi
new file mode 100644
index 0000000000..fa9d16a55a
--- /dev/null
+++ b/target/linux/ramips/dts/mt7621_tplink_rexx0-v1.dtsi
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		label-mac-device = &gmac0;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,57600";
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		wps {
+			label = "wps";
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+			linux,code = <KEY_WPS_BUTTON>;
+		};
+
+		power {
+			label = "power";
+			gpios = <&gpio 25 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+			linux,code = <KEY_POWER>;
+		};
+
+		led {
+			label = "led";
+			gpios = <&gpio 30 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+			linux,code = <KEY_LIGHTS_TOGGLE>;
+		};
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 31 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <40000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x0 0x20000>;
+				read-only;
+			};
+
+			partition@20000 {
+				compatible = "tplink,firmware";
+				label = "firmware";
+				reg = <0x20000 0xde0000>;
+			};
+
+			config: partition@e00000 {
+				label = "config";
+				reg = <0xe00000 0x50000>;
+				read-only;
+			};
+
+			/* range 0xe50000 to 0xff0000 is empty in vendor
+			 * firmware, so we do not use it either
+			 */
+
+			radio: partition@ff0000 {
+				label = "radio";
+				reg = <0xff0000 0x10000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&radio 0x0>;
+		mtd-mac-address = <&config 0x10008>;
+		mtd-mac-address-increment = <1>;
+		ieee80211-freq-limit = <2400000 2500000>;
+	};
+};
+
+&pcie1 {
+	wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&radio 0x8000>;
+		mtd-mac-address = <&config 0x10008>;
+		mtd-mac-address-increment = <2>;
+		ieee80211-freq-limit = <5000000 6000000>;
+	};
+};
+
+&gmac0 {
+	mtd-mac-address = <&config 0x10008>;
+};
+
+&switch0 {
+	ports {
+		port@0 {
+			status = "okay";
+			label = "lan";
+		};
+	};
+};