dt-bindings: mtd: Describe Rockchip RK3xxx NAND flash controller

Documentation support for Rockchip RK3xxx NAND flash controllers
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Yifeng Zhao <yifeng.zhao@rock-chips.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201210002134.5686-2-yifeng.zhao@rock-chips.com

Documentation/devicetree/bindings/mtd/rockchip,nand-controller.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/rockchip,nand-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Rockchip SoCs NAND FLASH Controller (NFC)
+
+allOf:
+  - $ref: "nand-controller.yaml#"
+
+maintainers:
+  - Heiko Stuebner <heiko@sntech.de>
+
+properties:
+  compatible:
+    oneOf:
+      - const: rockchip,px30-nfc
+      - const: rockchip,rk2928-nfc
+      - const: rockchip,rv1108-nfc
+      - items:
+          - const: rockchip,rk3036-nfc
+          - const: rockchip,rk2928-nfc
+      - items:
+          - const: rockchip,rk3308-nfc
+          - const: rockchip,rv1108-nfc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    items:
+      - description: Bus Clock
+      - description: Module Clock
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: ahb
+      - const: nfc
+
+  assigned-clocks:
+    maxItems: 1
+
+  assigned-clock-rates:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+patternProperties:
+  "^nand@[0-7]$":
+    type: object
+    properties:
+      reg:
+        minimum: 0
+        maximum: 7
+
+      nand-ecc-mode:
+        const: hw
+
+      nand-ecc-step-size:
+        const: 1024
+
+      nand-ecc-strength:
+        enum: [16, 24, 40, 60, 70]
+        description: |
+          The ECC configurations that can be supported are as follows.
+            NFC v600 ECC 16, 24, 40, 60
+              RK2928, RK3066, RK3188
+
+            NFC v622 ECC 16, 24, 40, 60
+              RK3036, RK3128
+
+            NFC v800 ECC 16
+              RK3308, RV1108
+
+            NFC v900 ECC 16, 40, 60, 70
+              RK3326, PX30
+
+      nand-bus-width:
+        const: 8
+
+      rockchip,boot-blks:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 2
+        default: 16
+        description:
+          The NFC driver need this information to select ECC
+          algorithms supported by the boot ROM.
+          Only used in combination with 'nand-is-boot-medium'.
+
+      rockchip,boot-ecc-strength:
+        enum: [16, 24, 40, 60, 70]
+        allOf:
+          - $ref: /schemas/types.yaml#/definitions/uint32
+        description: |
+          If specified it indicates that a different BCH/ECC setting is
+          supported by the boot ROM.
+            NFC v600 ECC 16, 24
+              RK2928, RK3066, RK3188
+
+            NFC v622 ECC 16, 24, 40, 60
+              RK3036, RK3128
+
+            NFC v800 ECC 16
+              RK3308, RV1108
+
+            NFC v900 ECC 16, 70
+              RK3326, PX30
+
+          Only used in combination with 'nand-is-boot-medium'.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/rk3308-cru.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    nfc: nand-controller@ff4b0000 {
+      compatible = "rockchip,rk3308-nfc",
+                   "rockchip,rv1108-nfc";
+      reg = <0xff4b0000 0x4000>;
+      interrupts = <GIC_SPI 81 IRQ_TYPE_LEVEL_HIGH>;
+      clocks = <&cru HCLK_NANDC>, <&cru SCLK_NANDC>;
+      clock-names = "ahb", "nfc";
+      assigned-clocks = <&clks SCLK_NANDC>;
+      assigned-clock-rates = <150000000>;
+
+      pinctrl-0 = <&flash_ale &flash_bus8 &flash_cle &flash_csn0
+                   &flash_rdn &flash_rdy &flash_wrn>;
+      pinctrl-names = "default";
+
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      nand@0 {
+        reg = <0>;
+        label = "rk-nand";
+        nand-bus-width = <8>;
+        nand-ecc-mode = "hw";
+        nand-ecc-step-size = <1024>;
+        nand-ecc-strength = <16>;
+        nand-is-boot-medium;
+        rockchip,boot-blks = <8>;
+        rockchip,boot-ecc-strength = <16>;
+      };
+    };
+
+...