activity-led usage

[Yegor Yefremov]

Hi Simon and Marek,

On Wed, Oct 1, 2025 at 1:09 AM Simon Glass <sjg at chromium.org> wrote:
>
> Hi Yegor,
>
> On Tue, 30 Sept 2025 at 08:48, Yegor Yefremov
> <yegorslists at googlemail.com> wrote:
> >
> > Hi Simon,
> >
> > On Tue, Sep 30, 2025 at 4:13 PM Simon Glass <sjg at chromium.org> wrote:
> > >
> > > 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.
> >
> > It is working now using your suggestion. Thanks.
> >
> > > >
> > > > Should activity-led be also mentioned in doc/device-tree-bindings/config.txt?
> > >
> > > We should be using /options/u-boot for this[1]
> >
> > This means, everything that can be found via the following command
> > won't work and should be removed?
> >
> > grep -r --include='*.dts[i]' boot-led arch/arm/dts
>
> Yes. I did a series to remove the legacy LED stuff last year but it
> wasn't applied because people wanted me to do more, probably what you
> are looking at doing now :-)

This would be great if this patch series could be merged. Marek has a
board (arch/arm/dts/stm32mp157a-dhcor-avenger96-u-boot.dtsi) that can
be reworked too.

AFAIK, led_activity_blink() is used very seldom. For example, in
cmd/ubi.c it is only used for writing [1]. mmc is omitted completely.
Is this intentional or is this functionality just missing?

[1] https://github.com/u-boot/u-boot/blob/master/cmd/ubi.c#L494

Regards,
Yegor