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From:   Sven Schuchmann <schuchmann@schleissheimer.de>
To:     Pavel Machek <pavel@ucw.cz>
CC:     Dan Murphy <dmurphy@ti.com>, Rob Herring <robh+dt@kernel.org>,
        "linux-leds@vger.kernel.org" <linux-leds@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: AW: [PATCH v1] leds: lp50xx: add setting of default intensity from DT
Thread-Topic: [PATCH v1] leds: lp50xx: add setting of default intensity from
 DT
Thread-Index: AQHW7lFOn/1Jlt56EkOy+ZVk/3cx2qpGlWAAgAAP4bA=
Date:   Wed, 3 Feb 2021 15:39:59 +0000
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References: <20210119105312.2636-1-schuchmann@schleissheimer.de>
 <20210203142940.GB12369@duo.ucw.cz>
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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.
>=20
> Do we need this to be configurable from device tree? Can we just set
> it to max or something?
>=20
> 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 w=
anted
to show the heartbeat in Red (half intensity):

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

                                        linux,default-trigger =3D "heartbea=
t";
                                        function =3D LED_FUNCTION_HEARTBEAT=
;

                                        led-9 {
                                                color =3D <LED_COLOR_ID_RED=
>;
                                                default-intensity =3D <100>=
;
                                        };

                                        led-10 {
                                                color =3D <LED_COLOR_ID_GRE=
EN>;
                                        };

                                        led-11 {
                                                color =3D <LED_COLOR_ID_BLU=
E>;
                                        };
                                };

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