activity-led usage

[Simon Glass]

Hi Yegor,

On Tue, 30 Sept 2025 at 06:35, Yegor Yefremov
<yegorslists at googlemail.com> wrote:
>
> On Tue, Sep 30, 2025 at 12:29 PM Yegor Yefremov
> <yegorslists at googlemail.com> wrote:
> >
> > Hi all,
> >
> > I added the following LED definition to the am335x-baltos.dts:
> >
> >         leds {
> >                 pinctrl-names = "default";
> >                 pinctrl-0 = <&user_leds>;
> >
> >                 compatible = "gpio-leds";
> >
> >                 led-power {
> >                         label = "led-red";
> >                         gpios = <&gpio3 0 GPIO_ACTIVE_LOW>;
> >                         default-state = "on";
> >                 };
> >         };
> >         user_leds: user-leds-pins {
> >                 pinctrl-single,pins = <
> >                         AM33XX_PADCONF(AM335X_PIN_MII1_COL,
> > PIN_OUTPUT_PULLDOWN, MUX_MODE7)     /* mii1_col.gpio3_0 PWR LED */
> >                 >;
> >         };
> >
> > The gpio-leds driver is working and I can toggle the led-red via the
> > led command.
> >
> > Then, I created an am335x-baltos-u-boot.dtsi file with the following content:
> >
> > / {
> >     config {
> >         u-boot,activity-led = "led-red";
> >     };
> > };
> >
> > I have also tried "led-power" instead of "led-red".
> >
> > In my final DTS files I have the following nodes:
> >
> >         leds {
> >                 pinctrl-names = "default";
> >                 pinctrl-0 = <0x56>;
> >                 compatible = "gpio-leds";
> >
> >                 led-power {
> >                         label = "led-red";
> >                         gpios = <0x57 0x00 0x01>;
> >                         default-state = "on";
> >                 };
> >         };
> >
> >         config {
> >                 u-boot,activity-led = "led-red";
> >         };
> >
> > U-Boot cannot find the activity-led node.
> > ofnode_options_get_by_phandle("activity-led", &led_node); returns -22,
> > because ofnode_path("/options/u-boot") fails.
> >
> > When driver debug is enabled, I also see the following messages:
> >
> > bind node config
> > Device 'config' has no compatible string
> >
> > My am335x-baltos-u-boot.dtsi code is similar to what I could find in
> > arch/arm/dts for the boot-led usage.
> >
> > Where should I debug further?

It is a bit confusing as there is still 'legacy' LED stuff in the
tree. For your problem I would suggest checking that the LED device is
configured correctly.

For sandbox in test.dts you can see:

    options {
        u-boot {
            compatible = "u-boot,config";
            boot-led = <&sandbox_led_green>;
            activity-led = <&sandbox_led_red>;
...
        };
    };

Check that led_init() is being called in the LED uclass.

>
> Should activity-led be also mentioned in doc/device-tree-bindings/config.txt?

We should be using /options/u-boot for this[1]

Regards,
Simon

[1] https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/options/u-boot.yaml