[source] ramips: add missing reset button for Nexx WT1520

[LEDE Commits]

mkresin pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/9601e6a0e2d0dd1b08ffc7d0ea4ef135dee1e0cf

commit 9601e6a0e2d0dd1b08ffc7d0ea4ef135dee1e0cf
Author: INAGAKI Hiroshi <musashino.open at gmail.com>
AuthorDate: Sun Nov 26 01:42:50 2017 +0900

    ramips: add missing reset button for Nexx WT1520
    
    This commit adds missing the GPIO key used as reset button.
    Nexx WT1520 has a GPIO key for factory reset, but it's not defined in
    WT1520.dtsi and cannot use it.
    
    Drop the UART (full) from the device tree source file, it was never
    used for this board. Adjust the kernel bootargs accordingly.
    
    Signed-off-by: INAGAKI Hiroshi <musashino.open at gmail.com>
    [add note about dropped UART (full) to the commit message]
    Signed-off-by: Mathias Kresin <dev at kresin.me>
---
 target/linux/ramips/dts/WT1520.dtsi | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/target/linux/ramips/dts/WT1520.dtsi b/target/linux/ramips/dts/WT1520.dtsi
index 4c889d1..0586c22 100644
--- a/target/linux/ramips/dts/WT1520.dtsi
+++ b/target/linux/ramips/dts/WT1520.dtsi
@@ -1,5 +1,8 @@
 #include "rt5350.dtsi"
 
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
 / {
 	compatible = "NEXXWT1520", "ralink,rt5350-soc";
 
@@ -8,21 +11,24 @@
 		reg = <0x0 0x2000000>;
 	};
 
-	chosen {
-		bootargs = "console=ttyS1,57600";
-	};
-};
+	gpio-keys-polled {
+		compatible = "gpio-keys-polled";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		poll-interval = <20>;
 
-&uart {
-	pinctrl-names = "default";
-	pinctrl-0 = <&uartf_pins>;
-	status = "okay";
+		reset {
+			label = "reset";
+			gpios = <&gpio0 10 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
 };
 
 &pinctrl {
 	state_default: pinctrl0 {
 		gpio {
-			ralink,group = "jtag";
+			ralink,group = "jtag", "uartf";
 			ralink,function = "gpio";
 		};
 	};