Re: [PATCH leds + devicetree v2 0/2] Parse DT property `trigger-sources` for netdev LED trigger

From: Pavel Machek
Date: Wed Nov 25 2020 - 05:39:50 EST


Hi!

> In this proposal the specific netdev LED trigger mode is determined
> from the `function` LED DT property.
>
> Example:
> eth0: ethernet@30000 {
> compatible = "xyz";
> #trigger-source-cells = <0>;
> };
>
> led {
> color = <LED_COLOR_ID_GREEN>;
> function = LED_FUNCTION_LINK;
> trigger-sources = <&eth0>;
> };

>
> When led is registered, the netdev trigger is automatically activated
> and set to light the LED on if eth0 is linked.
>
> Please let me know if this binding is OK, or if the binding should
> instead of the `function` property determine the trigger settings from
> arguments of the `trigger-sources` property :
> led {
> color = <LED_COLOR_ID_GREEN>;
> trigger-sources = <&eth0 (NETDEV_ATTR_LINK | NETDEV_ATTR_RX)>;
> };

So... Both interfaces look relatively sane.

I might preffer the second one. For development boards, the LEDs
really have no labels (etc), thus no function -- they are user LEDs 1
to 4. But we still may want to say "user LED one should have mmc0
trigger by default".

Of course, we might also want to simply say that the LED is really mmc LED...

> I prefer the first binding, since we already have the `function`
> property. Multiple modes can be achieved by string array, but this is
> not yet implemented:
> led {
> color = <LED_COLOR_ID_GREEN>;
> function = LED_FUNCTION_LINK, LED_FUNCTION_ACTIVITY;
> trigger-sources = <&eth0>;
> };

I don't see how multiple functions would work.

Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek

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