Re: [PATCH v2 1/2] dt-bindings: leds: add LED_FUNCTION for wlan2g/wlan5g

[Marek Behun <marek.behun@nic.cz>]

On Sat, 19 Sep 2020 21:24:26 +0200
Adrian Schmutzler <freifunk@adrianschmutzler.de> wrote:

> Many consumer "routers" have dedicated LEDs for specific WiFi bands,
> e.g. one for 2.4 GHz and one for 5 GHz. These LEDs specifically
> indicate the state of the relevant band, so the latter should be
> included in the function name. LED_FUNCTION_WLAN will remain for
> general cases or when the LED is used for more than one band.
> 
> This essentially is equivalent to how we use LED_FUNCTION_LAN and
> LED_FUNCTION_WAN instead of just having LED_FUNCTION_ETHERNET.

Dont. If you want the LED name to inform the user about the WiFi
device it is being triggered on, it instead should come from the
devicename part:
  "wlan0:blue:activity"

In fact the function should not be "wlan" (nor "wlan2g" or "wlan5g", but
"activity".

I am going to try to work on this subsystem so that if trigger source
of the LED is set to a WiFi device and function is set to activity, the
LED shall blink on wifi activity.

This way we can also avoid using the `linux,default-trigger` property
in favour of `function`, i.e. if I have:

   wlan0: wifi@12300 {
     compatible = "some-wifi";
     #trigger-source-cells = <0>;
   }

   led {
     color = <LED_COLOR_ID_BLUE>;
     function = LED_FUNCTION_ACTIVITY;
     trigger-sources = <&wlan0>;
   };

Than this will automatically name the LED as
  wlan0:blue:activity
and if the corresponding trigger is available, it should set the
trigger even if no `linux,default-trigger` property is present.

Marek