led: support led functionality on the bbb

led.go

@@ -0,0 +1,59 @@
+package embd
+
+type LED interface {
+	On() error
+	Off() error
+
+	Toggle() error
+
+	Close() error
+}
+
+type LEDDriver interface {
+	LED(key interface{}) (LED, error)
+
+	Close() error
+}
+
+var ledDriverInstance LEDDriver
+
+func InitLED() error {
+	desc, err := DescribeHost()
+	if err != nil {
+		return err
+	}
+
+	if desc.LEDDriver == nil {
+		return ErrFeatureNotSupport
+	}
+
+	ledDriverInstance = desc.LEDDriver()
+
+	return nil
+}
+
+func CloseLED() error {
+	return ledDriverInstance.Close()
+}
+
+func NewLED(key interface{}) (LED, error) {
+	return ledDriverInstance.LED(key)
+}
+
+func LEDOn(key interface{}) error {
+	led, err := NewLED(key)
+	if err != nil {
+		return err
+	}
+
+	return led.On()
+}
+
+func LEDOff(key interface{}) error {
+	led, err := NewLED(key)
+	if err != nil {
+		return err
+	}
+
+	return led.Off()
+}