new file mode 100644
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+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/qnap,mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: QNAP NAS on-board Microcontroller
+
+maintainers:
+ - Heiko Stuebner <heiko@sntech.de>
+
+description: |
+ QNAP embeds a microcontroller on their NAS devices adding system feature
+ as PWM Fan control, additional LEDs, power button status and more.
+
+properties:
+ compatible:
+ enum:
+ - qnap,ts433-mcu
+
+ "#cooling-cells":
+ const: 2
+
+ cooling-levels:
+ description: PWM duty cycle values corresponding to thermal cooling states.
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ items:
+ maximum: 255
+
+required:
+ - compatible
+
+additionalProperties: false
+
+examples:
+ - |
+ uart {
+ mcu {
+ compatible = "qnap,ts433-mcu";
+ #cooling-cells = <2>;
+ cooling-levels = <0 64 89 128 166 204 221 238>;
+ };
+ };
These MCUs can be found in network attached storage devices made by QNAP. They are connected to a serial port of the host device and provide functionality like LEDs, power-control and temperature monitoring. Signed-off-by: Heiko Stuebner <heiko@sntech.de> --- .../devicetree/bindings/mfd/qnap,mcu.yaml | 43 +++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 Documentation/devicetree/bindings/mfd/qnap,mcu.yaml