[RFC PATCH 6/7] realtek: Zyxel GS1900-8: define port LEDs

[Sander Vanheule]

Hi Oliver,

Thanks for all the feedback, I'll go over it tonight.  In the future, could you CC me (as the patch
author), other any reviewers, and people who were CC-ed before? Not everybody may be subscribed to
the mailing list (not even necessarily the patch author).

On Fri, 2022-07-29 at 14:58 +0200, Olliver Schinagl wrote:
> On 16-07-2022 21:09, Sander Vanheule wrote:
> > Add all port LEDs to the device tree for the GS1900-8. To reproduce the
> > same behaviour as stock firmware, the LEDs need to light up on all
> > link speeds, and blink on link activity:
> > 
> >      echo 1f > /sys/class/leds/lan?/rtl_hw_trigger
> >      echo realtek-switchport > /sys/class/leds/lan?/trigger
> > 
> > Signed-off-by: Sander Vanheule <sander at svanheule.net>
> > ---
> >   .../dts-5.10/rtl8380_zyxel_gs1900-8.dts       | 41 +++++++++++++++++++
> >   1 file changed, 41 insertions(+)
> > 
> > diff --git a/target/linux/realtek/dts-5.10/rtl8380_zyxel_gs1900-8.dts
> > b/target/linux/realtek/dts-5.10/rtl8380_zyxel_gs1900-8.dts
> > index e9c5efe60392..41266b701aca 100644
> > --- a/target/linux/realtek/dts-5.10/rtl8380_zyxel_gs1900-8.dts
> > +++ b/target/linux/realtek/dts-5.10/rtl8380_zyxel_gs1900-8.dts
> > @@ -10,3 +10,44 @@
> >   &gpio1 {
> >         /delete-node/ poe_enable;
> >   };
> > +
> > +&switchcore {
> > +       port-leds {
> > +               compatible = "realtek,rtl8380-port-led";
> > +               #address-cells = <2>;
> > +               #size-cells = <0>;
> > +
> > +               led at 8.0 {
> > +                       reg = <8 0>;
> > +                       label = "lan1";
> > +               };
> > +               led at 9.0 {
> > +                       reg = <9 0>;
> > +                       label = "lan2";
> > +               };
> > +               led at 10.0 {
> > +                       reg = <10 0>;
> > +                       label = "lan3";
> > +               };
> > +               led at 11.0 {
> > +                       reg = <11 0>;
> > +                       label = "lan4";
> > +               };
> > +               led at 12.0 {
> > +                       reg = <12 0>;
> > +                       label = "lan5";
> > +               };
> > +               led at 13.0 {
> > +                       reg = <13 0>;
> > +                       label = "lan6";
> > +               };
> > +               led at 14.0 {
> > +                       reg = <14 0>;
> > +                       label = "lan7";
> > +               };
> > +               led at 15.0 {
> > +                       reg = <15 0>;
> > +                       label = "lan8";
> > +               };
> > +       };
> > +};
> 
> nothing else to say then 'love it' :) I'm not familiar with the GS1900; 
> but it only has a single LED with one color?

That's correct. Each port on this device has one green LED to indicate status. I was lazy and didn't
add the 'color', 'function', 'function-enumerator' properties...

> Can we set the trigger 
> already here in the dt like we do with others?
> 
> arch/arm/boot/dts/am335x-bone-common.dtsi:31: linux,default-trigger = 
> "heartbeat";
> 
> for example ...

You actually can.  The trigger that reproduces stock behaviour is "realtek-switchport".  But! Before
you enable that trigger, you need to write an appropriate trigger mask to the custom config property
in /sys/class/leds/$PORT_LED. Otherwise the trigger value will be "disabled".  Setting that value
from DT is not possible though.  So I figured that the recommended way to configure this HW trigger
would be to run a script at system init.

Best,
Sander