dt-bindings: mtd: Add realtek,rtl9301-ecc

Add a dtschema for the ECC engine on the Realtek RTL93xx SoCs.
The engine supports BCH6 and BCH12 parity for 512 byte blocks.

The hardware can make use of interrupts but this is not yet
supported by the driver. From the known datasheets it is
connected to the LXB (lexra bus) and propably depends on its
clock. Provide an optional clock property that can describe
the relation.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Documentation/devicetree/bindings/mtd/realtek,rtl9301-ecc.yaml

@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/realtek,rtl9301-ecc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Realtek SoCs NAND ECC engine
+
+maintainers:
+  - Markus Stockhausen <markus.stockhausen@gmx.de>
+
+properties:
+  compatible:
+    const: realtek,rtl9301-ecc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    soc {
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        ecc0: ecc@1a600 {
+            compatible = "realtek,rtl9301-ecc";
+            reg = <0x1a600 0x54>;
+        };
+    };