dt-bindings: mtd: Convert stm32 fmc2-nand bindings to json-schema

Convert the STM32 fmc2-nand binding to DT schema format using json-schema
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
CC: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/mtd/st,stm32-fmc2-nand.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/st,stm32-fmc2-nand.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics Flexible Memory Controller 2 (FMC2) Bindings
+
+maintainers:
+  - Christophe Kerello <christophe.kerello@st.com>
+
+allOf:
+  - $ref: "nand-controller.yaml#"
+
+properties:
+  compatible:
+    const: st,stm32mp15-fmc2
+
+  reg:
+    items:
+      - description: Registers
+      - description: Chip select 0 data
+      - description: Chip select 0 command
+      - description: Chip select 0 address space
+      - description: Chip select 1 data
+      - description: Chip select 1 command
+      - description: Chip select 1 address space
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  dmas:
+    items:
+      - description: tx DMA channel
+      - description: rx DMA channel
+      - description: ecc DMA channel
+
+  dma-names:
+    items:
+      - const: tx
+      - const: rx
+      - const: ecc
+
+patternProperties:
+  "^nand@[a-f0-9]$":
+    type: object
+    properties:
+      nand-ecc-step-size:
+        const: 512
+
+      nand-ecc-strength:
+        enum: [1, 4 ,8 ]
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/stm32mp1-clks.h>
+    #include <dt-bindings/reset/stm32mp1-resets.h>
+    nand-controller@58002000 {
+      compatible = "st,stm32mp15-fmc2";
+      reg = <0x58002000 0x1000>,
+            <0x80000000 0x1000>,
+            <0x88010000 0x1000>,
+            <0x88020000 0x1000>,
+            <0x81000000 0x1000>,
+            <0x89010000 0x1000>,
+            <0x89020000 0x1000>;
+            interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
+            dmas = <&mdma1 20 0x10 0x12000a02 0x0 0x0>,
+                   <&mdma1 20 0x10 0x12000a08 0x0 0x0>,
+                   <&mdma1 21 0x10 0x12000a0a 0x0 0x0>;
+            dma-names = "tx", "rx", "ecc";
+            clocks = <&rcc FMC_K>;
+            resets = <&rcc FMC_R>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      nand@0 {
+        reg = <0>;
+        nand-on-flash-bbt;
+        #address-cells = <1>;
+        #size-cells = <1>;
+      };
+    };
+
+...

Documentation/devicetree/bindings/mtd/stm32-fmc2-nand.txt

-STMicroelectronics Flexible Memory Controller 2 (FMC2)
-NAND Interface
-
-Required properties:
-- compatible: Should be one of:
-              * st,stm32mp15-fmc2
-- reg: NAND flash controller memory areas.
-       First region contains the register location.
-       Regions 2 to 4 respectively contain the data, command,
-       and address space for CS0.
-       Regions 5 to 7 contain the same areas for CS1.
-- interrupts: The interrupt number
-- pinctrl-0: Standard Pinctrl phandle (see: pinctrl/pinctrl-bindings.txt)
-- clocks: The clock needed by the NAND flash controller
-
-Optional properties:
-- resets: Reference to a reset controller asserting the FMC controller
-- dmas: DMA specifiers (see: dma/stm32-mdma.txt)
-- dma-names: Must be "tx", "rx" and "ecc"
-
-* NAND device bindings:
-
-Required properties:
-- reg: describes the CS lines assigned to the NAND device.
-
-Optional properties:
-- nand-on-flash-bbt: see nand-controller.yaml
-- nand-ecc-strength: see nand-controller.yaml
-- nand-ecc-step-size: see nand-controller.yaml
-
-The following ECC strength and step size are currently supported:
- - nand-ecc-strength = <1>, nand-ecc-step-size = <512> (Hamming)
- - nand-ecc-strength = <4>, nand-ecc-step-size = <512> (BCH4)
- - nand-ecc-strength = <8>, nand-ecc-step-size = <512> (BCH8) (default)
-
-Example:
-
-	fmc: nand-controller@58002000 {
-		compatible = "st,stm32mp15-fmc2";
-		reg = <0x58002000 0x1000>,
-		      <0x80000000 0x1000>,
-		      <0x88010000 0x1000>,
-		      <0x88020000 0x1000>,
-		      <0x81000000 0x1000>,
-		      <0x89010000 0x1000>,
-		      <0x89020000 0x1000>;
-		interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
-		clocks = <&rcc FMC_K>;
-		resets = <&rcc FMC_R>;
-		pinctrl-names = "default";
-		pinctrl-0 = <&fmc_pins_a>;
-		#address-cells = <1>;
-		#size-cells = <0>;
-
-		nand@0 {
-			reg = <0>;
-			nand-on-flash-bbt;
-			#address-cells = <1>;
-			#size-cells = <1>;
-		};
-	};