board/aarch64/r2s: map board LEDs to Infix system LEDs

The R2S has a minimal set of system LEDs, all of which are single color.
This commit tries to distill and map the essence of the Infix functions
to available LEDs.

The SYS LED is turned on (fainy red) at power-on, when U-Boot has loaded
the kernel it turns the SYS LED bright red on.  The idea is then to turn
the red SYS LED off as soon as the system has successfully loaded system
startup-config, and then turn the green LAN LED on.  Indicating that the
both the device is operational and that the user can connect to the LAN
port.

The WAN LED is given a "wan-up" input condition, with the intention of
turning it on (green) when the device has acquired a DHCP address.

The failure modes, which in many ways is the essence of Infix signaling,
are fail-safe and panic, triggered by loading failure-config, or failing
to loadd failure-config, respectively.  In fail-safe mode the SYS LED is
blinking red at 5 Hz and in panic mode *all* LEDs blink at 5 Hz.

Issue #276

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

board/aarch64/r2s/README.md

@@ -8,6 +8,46 @@ The R2S does not have any onboard eMMC, so the only way to boot Infix on
 it is using and SD card.
 
 
+LEDs
+----
+
+The front system LEDs work as follows in Infix:
+
+| **Stage**      | **SYS** | **LAN** | **WAN** |
+|----------------|---------|---------|---------|
+| Power-on       | dimmed  | off     | off     |
+| Linux loading  | on      | off     | off     |
+| System loading | 1 Hz    | off     | off     |
+| System up      | off     | on      | off     |
+| WAN address    | off     | on      | on      |
+| Locate         | 1 Hz    | 1 Hz    | 1 Hz    |
+| Fail safe      | 5 Hz    | off     | off     |
+| Panic          | 5 Hz    | 5 Hz    | 5 Hz    |
+
+Powering on the device the SYS LED is turned on faintly (dimmed).  It
+remains dimmed while U-Boot loads the kernel, and turns bright red when
+the kernel starts.  It remains steady on until the system has started
+the LED daemon, `iitod`, which sets it blinking at 1 Hz while the rest
+of the system starts up.  When the system has come up successfully, the
+SYS LED is turned off and the green LAN LED turns on.  The WAN LED will
+turn on (green) when the WAN interface is up and has an IP address.
+
+> Compared to the `x86_64` Qemu target, it takes a while to parse all
+> YANG models and load `startup-config`, but the whole process should
+> not take more than 60 seconds, and usually a lot less.
+
+If a "find my device" function exists, it will blink all LEDs at 1 Hz.
+
+If `startup-config` fails to load Ínfix reverts to `failure-config`,
+putting the device in fail safe (or fail secure) mode.  Indicated by
+the SYS LED blinking at 5 Hz instead of turning off.
+
+If Infix for some reason also fails to load `failure-config`, then all
+LEDs will blink at 5 Hz to clearly indicate something is very wrong.
+
+In all error cases the console shows the problem.
+
+
 How to Build
 ------------
 

board/aarch64/r2s/rootfs/etc/iitod.json

@@ -0,0 +1,91 @@
+{
+    "input": {
+	"path": {
+	    "locate":       { "path": "/run/led/locate" },
+
+	    "status-prime": { "path": "/run/led/status-prime" },
+	    "status-ok":    { "path": "/run/led/status-ok" },
+	    "status-err":   { "path": "/run/led/status-err" },
+	    "status-crit":  { "path": "/run/led/status-crit" },
+
+	    "fault-prime":  { "path": "/run/led/fault-prime" },
+	    "fault-ok":     { "path": "/run/led/fault-ok" },
+	    "fault-err":    { "path": "/run/led/fault-err" },
+	    "fault-crit":   { "path": "/run/led/fault-crit" },
+
+	    "wan-up":       { "path": "/run/led/wan-up" },
+
+	    "startup":   { "path": "/run/finit/cond/run/startup/success" },
+	    "fail-safe": { "path": "/run/finit/cond/run/failure/success" },
+	    "panic":     { "path": "/run/finit/cond/run/failure/failure" }
+	},
+	"udev": {
+	    "power-a": { "subsystem": "power_supply" },
+	    "power-b": { "subsystem": "power_supply" }
+	}
+    },
+
+    "output": {
+	"led-group": {
+	    "port-link-act": {
+		"match": ["*:green:tp", "*:green:sfp", "*:green:port" ],
+
+		"rules": [
+		    { "if": "true", "then": { "trigger": "netdev", "link": 1, "rx": 1, "tx": 1 } }
+		]
+	    },
+	    "port-alarm": {
+		"match": ["*:yellow:tp", "*:yellow:sfp", "*:yellow:port" ],
+
+		"rules": [
+		]
+	    }
+	},
+	"led": {
+	    "nanopi-r2s:red:sys": {
+		"rules": [
+		    { "if": "locate",    "then": "@blink-1hz" },
+		    { "if": "panic",     "then": "@blink-5hz" },
+		    { "if": "fail-safe", "then": "@blink-5hz" },
+		    { "if": "startup",   "then": "@off" },
+		    { "if": "true",      "then": "@blink-1hz" }
+		]
+	    },
+
+	    "nanopi-r2s:green:lan": {
+		"rules": [
+		    { "if": "locate",  "then": "@blink-1hz" },
+		    { "if": "panic",   "then": "@blink-5hz" },
+		    { "if": "startup", "then": "@on" }
+		]
+	    },
+
+	    "nanopi-r2s:green:wan": {
+		"rules": [
+		    { "if": "locate", "then": "@blink-1hz" },
+		    { "if": "panic",  "then": "@blink-5hz" },
+		    { "if": "wan-up", "then": "@on" }
+		]
+	    }
+	}
+    },
+
+    "aliases": {
+	"on": {
+	    "brightness": true
+	},
+	"off": {
+	    "brightness": false
+	},
+	"blink-1hz": {
+	    "trigger": "timer",
+	    "delay_on": 500,
+	    "delay_off": 500
+	},
+	"blink-5hz": {
+	    "trigger": "timer",
+	    "delay_on": 100,
+	    "delay_off": 100
+	}
+    }
+}