[PATCH v18 1/2] dt-bindings: embedded-controller: Add synology microp devices

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.

The device has a different feature set depending on the Synology NAS
model, like having different number of fans, buttons and leds. Depending
on the architecture of the model, they also need a different system
shutdown behaviour.

Reviewed-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Markus Probst <[email protected]>
---
 .../synology,ds918p-microp.yaml                    | 100 +++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/Documentation/devicetree/bindings/embedded-controller/synology,ds918p-microp.yaml b/Documentation/devicetree/bindings/embedded-controller/synology,ds918p-microp.yaml
new file mode 100644
index 000000000000..a44101884322
--- /dev/null
+++ b/Documentation/devicetree/bindings/embedded-controller/synology,ds918p-microp.yaml
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/embedded-controller/synology,ds918p-microp.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synology NAS on-board Microcontroller
+
+maintainers:
+  - Markus Probst <[email protected]>
+
+description: |
+  Synology Microp is a microcontroller found in Synology NAS devices.
+  It is connected to a serial port on the host device.
+
+  It is necessary to properly shutdown and reboot the NAS device and
+  provides additional functionality such as led control, fan speed control,
+  a beeper and buttons on the NAS device.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - synology,rs1221rpp-microp
+              - synology,rs822p-microp
+              - synology,rs422p-microp
+          - const: synology,rs1221p-microp
+
+      - items:
+          - const: synology,ds1825p-microp
+          - const: synology,ds1823xsp-microp
+
+      - items:
+          - enum:
+              - synology,ds725p-microp
+              - synology,ds225p-microp
+              - synology,ds723p-microp
+              - synology,ds710p-microp
+          - const: synology,ds214play-microp
+
+      - items:
+          - enum:
+              - synology,ds425p-microp
+              - synology,ds1525p-microp
+              - synology,ds925p-microp
+              - synology,ds923p-microp
+              - synology,ds1522p-microp
+              - synology,ds1010p-microp
+              - synology,ds411p-microp
+          - const: synology,ds918p-microp
+
+      - items:
+          - enum:
+              - synology,ds124-microp
+              - synology,ds223j-microp
+              - synology,ds223-microp
+          - const: synology,ds118-microp
+
+      - enum:
+          - synology,ds118-microp
+          - synology,ds1823xsp-microp
+          - synology,rs1221p-microp
+          - synology,ds918p-microp
+          - synology,ds214play-microp
+
+  fan-failure-gpios:
+    description: GPIOs needed to determine which fans stopped working on a fan failure event.
+    minItems: 2
+    maxItems: 3
+
+required:
+  - compatible
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - synology,ds918p-microp
+              - synology,rs422p-microp
+    then:
+      required:
+        - fan-failure-gpios
+    else:
+      properties:
+        fan-failure-gpios: false
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    embedded-controller {
+      compatible = "synology,ds923p-microp", "synology,ds918p-microp";
+
+      fan-failure-gpios = <&gpio 68 GPIO_ACTIVE_HIGH>, <&gpio 69 GPIO_ACTIVE_HIGH>;
+    };

-- 
2.54.0