board/aarch64/r2s: add u-boot factory-reset button detect

Allow reset button on the R2S to be used for factory reset at power-on.
See board README for details.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

board/aarch64/r2s/README.md

@@ -16,6 +16,7 @@ The front system LEDs work as follows in Infix:
 | **Stage**      | **SYS** | **LAN** | **WAN** |
 |----------------|---------|---------|---------|
 | Power-on       | dimmed  | off     | off     |
+| Factory reset  | on      | on      | on      |
 | Linux loading  | on      | off     | off     |
 | System loading | 1 Hz    | off     | off     |
 | System up      | off     | on      | off     |
@@ -48,6 +49,28 @@ LEDs will blink at 5 Hz to clearly indicate something is very wrong.
 In all error cases the console shows the problem.
 
 
+Factory Reset
+-------------
+
+The reset button on the side can be used not only to safely reboot the
+device, but can also be used to trigger a factory reset at power on.
+
+At power-on, keep the reset button pressed for 10 seconds.  The system
+LEDs (SYS, WAN, LAN) will all blink at 1 Hz, to help you count down the
+seconds.  When the 10 seconds have passed all LEDs are turned off before
+loading Linux.
+
+When Linux boots up it confirms the factory reset by lighting up the
+LEDs again, no blinking this time.  The LEDs stay on until all files and
+directories on read/writable partitions (`/cfg` and `/var`) have been
+safely erased.
+
+The system then continues loading, turning off all LEDs except SYS,
+which blinks calmly at 1 Hz as usual until the system has completed
+loading, this time with a `startup-config` freshly restored from the
+device's `factory-config`.
+
+
 How to Build
 ------------
 

board/aarch64/r2s/uboot/extras.config

@@ -1,3 +1,9 @@
+CONFIG_BUTTON=y
+CONFIG_BUTTON_GPIO=y
+
+CONFIG_LED=y
+CONFIG_LED_GPIO=y
+
 # CONFIG_MMC_PCI is not set
 CONFIG_DEVICE_TREE_INCLUDES="infix-env.dtsi infix-key.dtsi r2s-env.dtsi"
 CONFIG_SYS_PROMPT="(r2s) "

board/aarch64/r2s/uboot/r2s-env.dtsi

@@ -6,7 +6,42 @@
 
 			/* This is a development platform, hard code developer mode */
 			ixbtn-devmode = "setenv dev_mode yes; echo Enabled";
-			ixbtn-factory = "echo \"No button available, use bootmenu\"";
+
+			/* Override default definitiion to add LED feedback */
+                        ixbtn-factory = "
+if button factory-reset; then
+    echo \"Keep button pressed for 10 seconds to engage factory reset ...\"
+
+    for tick in . . . . . . . . . .; do
+        led nanopi-r2s:red:sys   on
+        led nanopi-r2s:green:lan on
+        led nanopi-r2s:green:wan on
+        sleep 0.5
+        led nanopi-r2s:red:sys   off
+        led nanopi-r2s:green:lan off
+        led nanopi-r2s:green:wan off
+        sleep 0.5
+        echo -n \"Checking button: \"
+        button factory-reset || exit
+    done
+
+    echo -n \"Final button check: \"
+    if button factory-reset; then
+        setenv factory_reset yes
+        echo \"FACTORY RESET ENGAGED\"
+    fi
+fi
+";
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		factory-reset {
+			gpios = <&gpio0 0 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_POWER>;
+			label = "factory-reset";
 		};
 	};
 };