Merge patch series "led: remove u-boot,boot-led and u-boot,error-led + add cmd doc"

Quentin Schulz <[email protected]> says:

u-boot,boot-led and u-boot,error-led aren't actually handled by some
generic code but rather by board or architecture specific code. They
also aren't properties that are part of the official dt-binding so they
cannot be upstreamed. For u-boot,boot-led, there's actually a proper
replacement which is /options/u-boot/boot-led[1] (+ CONFIG_LED_BOOT=y).

For Rockchip boards, either nothing (for RK3066, PX30 and RK3399) was
using that property or (for RK3188) the code handling it was guarded by
symbols that were not enabled in the defconfig. For those, the property
and guarded code are removed.

For the Sam9x60 Curiosity, it seems that even though the LED is
controlled whenever CONFIG_LED is enabled, it isn't enabled by default
in the defconfig (but the code was added without modifying the
defconfig, explicitly leaving a choice to the user). I decided to keep
that feature by simply migrating it to the new API, though I cannot test
it as I do not own the device.

The STM32 boards will be migrated in the near future once their upstream
(kernel) Device Trees gain the new way to specify this (via
/options/u-boot/boot-led). I'll let Patrice handle this, see
https://lore.kernel.org/u-boot/[email protected]/
and
https://lore.kernel.org/u-boot/[email protected]/

After this, only one user of u-boot,boot-led will be left, based on
STM32: board/dhelectronics/dh_stm32mp1/board.c. @Patrice, maybe that's
something you want to have a look at as well, this seems to be some
evaluation kit?

The only users of u-boot,error-led are STM32 boards, so I'll leave this
to Patrice as well, I do not know what's the way to go for that one.

In any case, I would like to not encourage people to use out-of-spec DT
properties when there is another option (u-boot,boot-led), so I remove
the properties from the dt-binding document from U-Boot.

The help text for the blink subcommand of the led command was misleading
so this is now fixed.

This also moves the content of doc/README.LED into the doc/api/led.rst,
while clearly stating one shouldn't be using this anymore.

This also gets rid of dt-binding that we already have in dts/upstream.

Finally, this adds documentation for the led shell command.

[1] https://github.com/devicetree-org/dt-schema/blob/v2025.08/dtschema/schemas/options/u-boot.yaml#L113-L116

Link: https://lore.kernel.org/r/[email protected]

1 files changed, 95 insertions, 0 deletions

diff --git a/doc/usage/cmd/led.rst b/doc/usage/cmd/led.rst
new file mode 100644
index 00000000000..b5623895c7e
--- /dev/null
+++ b/doc/usage/cmd/led.rst
@@ -0,0 +1,95 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+.. index::
+   single: led (command)
+
+led command
+===========
+
+Synopsis
+--------
+
+::
+
+    led <led_label> <on|off|toggle>
+    led <led_label> blink <blink-freq in ms>
+    led <led_label>
+    led list
+
+led <led_label>
+---------------
+
+Get state of the LED whose label is the one passed as ``<led_label>`` argument.
+
+Provided ``<led_label>`` is *module_led*, the possible outputs for this command
+are::
+
+    LED 'module_led': off
+    LED 'module_led': on
+    LED 'module_led': blink
+
+led <led_label> on|off|toggle
+-----------------------------
+
+Turn on, off or toggle state of the LED whose label is the one passed as
+``<led_label>`` argument.
+
+led <led_label> blink <blink-freq in ms>
+----------------------------------------
+
+Make the LED whose label is the one passed as ``<led_label>`` argument blink at
+a frequency specified by the argument ``<blink-freq in ms>``.
+
+The frequency is parsed as a decimal number and its unit is milliseconds. The
+duty cycle is 50%. Example::
+
+    led blue blink 1000
+
+will make the *blue*-labeled LED blink with a state (on or off) kept for 500ms
+before switching to the other state (respectively off or on) for 500ms,
+looping endlessly.
+
+led list
+--------
+
+List all available LEDs by their label and provide their known state, which can
+be either *off*, *on* or *blink*.
+
+If a LED has not been probed yet, its state will be shown as *<inactive>* in the
+list.
+
+Examples
+--------
+
+::
+
+    => led list
+    module_led      on
+    sd_card_led     <inactive>
+    => led module_led
+    LED 'module_led': on
+    => led module_led off
+    => led module_led
+    LED 'module_led': off
+    => led module_led toggle
+    => led module_led
+    LED 'module_led': on
+    => led module_led toggle
+    => led module_led
+    LED 'module_led': off
+    => led module_led blink 1000
+    => led module_led
+    LED 'module_led': blink
+    => led sd_card_led
+    LED 'sd_card_led': off
+    => led list
+    module_led      blink
+    sd_card_led     off
+
+Configuration
+-------------
+
+The *led* commands are only available if ``CONFIG_CMD_LED=y``.
+
+The *led <led_label> blink* command is only available if ``CONFIG_CMD_LED=y``
+and either ``CONFIG_LED_BLINK=y`` or ``CONFIG_LED_SW_BLINK=y``.