AW: [PATCH v1] leds: lp50xx: add setting of default intensity from DT

From: Sven Schuchmann
Date: Wed Feb 03 2021 - 10:43:30 EST


Hello Pavel,

> > In order to use a multicolor-led together with a trigger
> > from DT the led needs to have an intensity set to see something.
> > The trigger changes the brightness of the led but if there
> > is no intensity we actually see nothing.
> >
> > This patch adds the ability to set the default intensity
> > of each led so that it is turned on from DT.
>
> Do we need this to be configurable from device tree? Can we just set
> it to max or something?
>
> Aha, this basically sets the initial color for LEDs the monochromatic
> triggers, right?

Let me try to explain in other words: I have one RGB-LED
which consists of 3 Colors. Each of the three colors (Red, Green, Blue) you have
to define in the DT. For example this is my setup for one RGB-LED which I wanted
to show the heartbeat in Red (half intensity):

multi-led@3 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0x3>;
color = <LED_COLOR_ID_RGB>;

linux,default-trigger = "heartbeat";
function = LED_FUNCTION_HEARTBEAT;

led-9 {
color = <LED_COLOR_ID_RED>;
default-intensity = <100>;
};

led-10 {
color = <LED_COLOR_ID_GREEN>;
};

led-11 {
color = <LED_COLOR_ID_BLUE>;
};
};

If I would not have the default-intensity I would actually see nothing,
since the intensity (which goes from 0-255) of each led is initialized with 0.

I hope I could clarify this a little more?

Best Regards,

Sven