[PATCH 4/8] dt-bindings: mfd: Add AAEON embedded controller binding

["Thomas Perrot (Schneider Electric)" <thomas.perrot@bootlin.com>]

Add device tree binding documentation for the AAEON embedded controller
(MCU). This microcontroller is found on AAEON embedded boards and provides
system features such as GPIO control, watchdog timer, and LED management.

The MCU is connected via I2C and acts as a multi-function device with
GPIO and watchdog as child nodes.

Signed-off-by: Thomas Perrot (Schneider Electric) <thomas.perrot@bootlin.com>
---
 .../bindings/mfd/aaeon,srg-imx8pl-mcu.yaml         | 58 ++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/aaeon,srg-imx8pl-mcu.yaml b/Documentation/devicetree/bindings/mfd/aaeon,srg-imx8pl-mcu.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..680d06a7e7cb3754bdfc67a1b8c484811eba55d1
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/aaeon,srg-imx8pl-mcu.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/aaeon,srg-imx8pl-mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AAEON Embedded Controller
+
+maintainers:
+  - Jérémie Dautheribes <jeremie.dautheribes@bootlin.com>
+  - Thomas Perrot <thomas.perrot@bootlin.com>
+
+description: |
+  AAEON embeds a microcontroller on their embedded boards providing system
+  features such as GPIO control, watchdog timer, and LED management.
+  The MCU is connected via I2C bus.
+
+properties:
+  compatible:
+    const: aaeon,srg-imx8pl-mcu
+
+  reg:
+    maxItems: 1
+
+  gpio:
+    $ref: /schemas/gpio/aaeon,srg-imx8pl-gpio.yaml
+
+  watchdog:
+    $ref: /schemas/watchdog/aaeon,srg-imx8pl-wdt.yaml
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      aaeon_mcu: embedded-controller@62 {
+        compatible = "aaeon,srg-imx8pl-mcu";
+        reg = <0x62>;
+
+        gpio {
+          compatible = "aaeon,srg-imx8pl-gpio";
+          gpio-controller;
+          #gpio-cells = <2>;
+          ngpios = <19>;
+        };
+
+        watchdog {
+          compatible = "aaeon,srg-imx8pl-wdt";
+        };
+      };
+    };

-- 
2.52.0