ramips: Add support for the GnuBee Personal Cloud Two

The GnuBee Personal Cloud Two crowdfunded on https://www.crowdsupply.com
It is a low-cost, low-power, network-attached storage device.

Specifications:

- SoC: MediaTek MT7621AT
- RAM: DDR3 512 MB
- Flash: 32 MB
- Six SATA ports for 3.5" Drives
- One SDcard
- One USB 3.0
- Two USB 2.0
- Gigabit Ethernet: Three Ports
- UART 3.5mm Audio Jack or 3 pin header - 57600 8N1
- Three GPIOs available on a pin header

Flash instructions:

The GnuBee Personal Cloud Two ships with libreCMC installed.
libreCMC is a Free Software Foundation approved fork of LEDE/OpenWrt.
As such one can upgrade using the webinterface or sysupgrade.

Das U-Boot has multiple options for recovery or updates including :

- USB
- http
- tftp

Errata:
- While there are three ethernet ports, the third requires support for
  the second GMAC. This will come in kernel 4.14.
- The first hard drive slot has a clearance issue with the two fan
  headers. Workaround is to pull the headers out and connect the pins to
  jumper wires.
- Using this device as a NAS is problematic with the 4.9 kernel as many
  /dev/sdX reads throw silent errors. The current theory behind this is
  some kind of unhandled DMA mapping error in the kernel. This is not an
  issue with kernel 4.4.

Signed-off-by: L. D. Pinney <ldpinney@gmail.com>
Signed-off-by: Rosen Penev <rosenp@gmail.com>

1 files changed, 137 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/GB-PC2.dts b/target/linux/ramips/dts/GB-PC2.dts
new file mode 100644
index 0000000..f31ac2b
--- /dev/null
+++ b/target/linux/ramips/dts/GB-PC2.dts
@@ -0,0 +1,137 @@
+/dts-v1/;
+
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	compatible = "gnubee,gb-pc2", "mediatek,mt7621-soc";
+	model = "GB-PC2";
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x1c000000>, <0x20000000 0x4000000>;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,57600";
+	};
+
+	palmbus: palmbus@1E000000 {
+		i2c@900 {
+			status = "okay";
+		};
+	};
+
+	gpio-keys-polled {
+		compatible = "gpio-keys-polled";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		poll-interval = <20>;
+
+		reset {
+			label = "reset";
+			gpios = <&gpio0 18 GPIO_ACTIVE_HIGH>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+
+	gpio-leds {
+		compatible = "gpio-leds";
+
+		system {
+			label = "gb-pc2:green:system";
+			gpios = <&gpio0 6 GPIO_ACTIVE_LOW>;
+		};
+
+		status {
+			label = "gb-pc2:green:status";
+			gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
+		};
+
+		lan {
+			label = "gb-pc2:green:lan";
+			gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
+		};
+
+		wan {
+			label = "gb-pc2:green:wan";
+			gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;
+		};
+
+		eth1-y {
+			label = "gb-pc2:yellow:eth1-y";
+			gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+		};
+
+		eth1-g {
+			label = "gb-pc2:green:eth1-g";
+			gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+		};
+
+	};
+};
+
+&sdhci {
+	status = "okay";
+};
+
+&spi0 {
+	status = "okay";
+
+	m25p80@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <10000000>;
+		m25p,chunked-io = <32>;
+
+		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 {
+			label = "firmware";
+			reg = <0x50000 0x1fb0000>;
+		};
+	};
+};
+
+&cpuclock {
+			compatible = "fixed-clock";
+			clock-frequency = <900000000>;
+};
+
+&pcie {
+	status = "okay";
+};
+
+&ethernet {
+	mtd-mac-address = <&factory 0xe000>;
+};
+
+&pinctrl {
+	state_default: pinctrl0 {
+		gpio {
+			ralink,group = "uart3";
+			ralink,function = "gpio";
+		};
+	};
+};
+