Add the Synology Microp devicetree bindings. Those devices are
microcontrollers found on Synology NAS devices. They are connected to a
serial port on the host device.

Those devices are used to control certain LEDs, fan speeds, a beeper, to
handle buttons, fan failures and to properly shutdown and reboot the
device.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
---
 .../devicetree/bindings/mfd/synology,microp.yaml   | 49 ++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/synology,microp.yaml b/Documentation/devicetree/bindings/mfd/synology,microp.yaml
new file mode 100644
index 000000000000..60609bb19b66
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/synology,microp.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/synology,microp.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synology NAS on-board Microcontroller
+
+maintainers:
+  - Markus Probst <markus.probst@posteo.de>
+
+description:
+  Synology devices contain a microcontroller on their device to control
+  certain leds, fan speeds, a beeper, to properly handle system shutdown
+  and reboot, buttons and fan failures.
+
+properties:
+  compatible:
+    const: synology,microp
+
+patternProperties:
+  "^(power|status|alert|usb)-led$":
+    $ref: /schemas/leds/common.yaml
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - power-led
+  - status-led
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    mcu {
+      compatible = "synology,microp";
+
+      power-led {
+        color = <LED_COLOR_ID_BLUE>;
+        function = LED_FUNCTION_POWER;
+      };
+
+      status-led {
+        color = <LED_COLOR_ID_MULTI>;
+        function = LED_FUNCTION_STATUS;
+      };
+    };

-- 
2.52.0

On 08/03/2026 19:41, Markus Probst wrote:
> Add the Synology Microp devicetree bindings. Those devices are
> microcontrollers found on Synology NAS devices. They are connected to a
> serial port on the host device.
> 
> Those devices are used to control certain LEDs, fan speeds, a beeper, to
> handle buttons, fan failures and to properly shutdown and reboot the
> device.
> 
> Signed-off-by: Markus Probst <markus.probst@posteo.de>
> ---
>  .../devicetree/bindings/mfd/synology,microp.yaml   | 49 ++++++++++++++++++++++

This is not an "MFD" device.

...

> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/leds/common.h>
> +
> +    mcu {

Please read previous comments.

Best regards,
Krzysztof