auxdisplay: lcd2s DT binding doc

Add a binding doc for the modtronix lcd2s auxdisplay driver. It also
adds modtronix to the list of known vendor-prefixes.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Documentation/devicetree/bindings/auxdisplay/modtronix,lcd2s.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/modtronix,lcd2s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Modtronix engineering LCD2S Character LCD Display
+
+maintainers:
+  - Lars Poeschel <poeschel@lemonage.de>
+
+description:
+  The LCD2S is a Character LCD Display manufactured by Modtronix Engineering.
+  The display supports a serial I2C and SPI interface. The driver currently
+  only supports the I2C interface.
+
+properties:
+  compatible:
+    const: modtronix,lcd2s
+
+  reg:
+    maxItems: 1
+    description:
+      I2C bus address of the display.
+
+  display-height-chars:
+    description: Height of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 4
+
+  display-width-chars:
+    description: Width of the display, in character cells.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 16
+    maximum: 20
+
+required:
+  - compatible
+  - reg
+  - display-height-chars
+  - display-width-chars
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      lcd2s: auxdisplay@28 {
+        compatible = "modtronix,lcd2s";
+        reg = <0x28>;
+        display-height-chars = <4>;
+        display-width-chars = <20>;
+      };
+    };

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -681,6 +681,8 @@ patternProperties:
     description: MiraMEMS Sensing Technology Co., Ltd.
   "^mitsubishi,.*":
     description: Mitsubishi Electric Corporation
+  "^modtronix,.*":
+    description: Modtronix Engineering
   "^mosaixtech,.*":
     description: Mosaix Technologies, Inc.
   "^motorola,.*":