[PATCHv3] dt-bindings: mtd: convert IBM NDFC binding to YAML

[PATCHv3] dt-bindings: mtd: convert IBM NDFC binding to YAML

[Rosen Penev]

The NDFC NAND flash controller was only described in a legacy text file,
so dtbs_check reported "failed to match any schema with compatible:
['ibm,ndfc']" for the ndfc nodes of the bluestone, canyonlands, eiger,
glacier, sequoia and warp device trees.

Convert the binding to the YAML format so those nodes match the generic
nand-controller-legacy schema.  Describe the node's reg, ccr and
bank-settings properties, along with its "nand" chip node which carries
the legacy partition layout.

Assisted-by: LLM
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v3: fix wrong regex
 v2: fix reg value
 .../devicetree/bindings/mtd/ibm,ndfc.txt      | 39 --------
 .../devicetree/bindings/mtd/ibm,ndfc.yaml     | 88 +++++++++++++++++++
 2 files changed, 88 insertions(+), 39 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/mtd/ibm,ndfc.txt
 create mode 100644 Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml

diff --git a/Documentation/devicetree/bindings/mtd/ibm,ndfc.txt b/Documentation/devicetree/bindings/mtd/ibm,ndfc.txt
deleted file mode 100644
index 869f0b5f16e8..000000000000
--- a/Documentation/devicetree/bindings/mtd/ibm,ndfc.txt
+++ /dev/null
@@ -1,39 +0,0 @@
-AMCC NDFC (NanD Flash Controller)
-
-Required properties:
-- compatible : "ibm,ndfc".
-- reg : should specify chip select and size used for the chip (0x2000).
-
-Optional properties:
-- ccr : NDFC config and control register value (default 0).
-- bank-settings : NDFC bank configuration register value (default 0).
-
-Notes:
-- partition(s) - follows the OF MTD standard for partitions
-
-Example:
-
-ndfc@1,0 {
-	compatible = "ibm,ndfc";
-	reg = <0x00000001 0x00000000 0x00002000>;
-	ccr = <0x00001000>;
-	bank-settings = <0x80002222>;
-	#address-cells = <1>;
-	#size-cells = <1>;
-
-	nand {
-		#address-cells = <1>;
-		#size-cells = <1>;
-
-		partition@0 {
-			label = "kernel";
-			reg = <0x00000000 0x00200000>;
-		};
-		partition@200000 {
-			label = "root";
-			reg = <0x00200000 0x03E00000>;
-		};
-	};
-};
-
-
diff --git a/Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml b/Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml
new file mode 100644
index 000000000000..e614c5855b42
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml
@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/ibm,ndfc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: IBM/AMCC NDFC (NAND Flash Controller)
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+  - Richard Weinberger <richard@nod.at>
+
+description: |
+  The NDFC is the NAND flash controller integrated into the IBM/AMCC
+  PowerPC 44x SoCs.
+
+allOf:
+  - $ref: nand-controller-legacy.yaml#
+
+properties:
+  compatible:
+    const: ibm,ndfc
+
+  reg:
+    description: Chip select and size used for the chip.
+    maxItems: 1
+
+  ccr:
+    description: NDFC config and control register value.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  bank-settings:
+    description: NDFC bank configuration register value.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  nand:
+    type: object
+    description: NAND chip attached to the controller.
+
+    properties:
+      "#address-cells":
+        const: 1
+      "#size-cells":
+        const: 1
+
+    patternProperties:
+      "^partition@[0-9a-f]+$":
+        $ref: /schemas/mtd/partitions/partition.yaml#/$defs/partition-node
+        deprecated: true
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    ebc {
+        #address-cells = <2>;
+        #size-cells = <1>;
+
+        ndfc@1,0 {
+            compatible = "ibm,ndfc";
+            reg = <0x00000001 0x00000000 0x00002000>;
+            ccr = <0x00001000>;
+            bank-settings = <0x80002222>;
+            #address-cells = <1>;
+            #size-cells = <1>;
+
+            nand {
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                partition@0 {
+                    label = "kernel";
+                    reg = <0x00000000 0x00200000>;
+                };
+                partition@200000 {
+                    label = "root";
+                    reg = <0x00200000 0x03e00000>;
+                };
+            };
+        };
+    };
+...
-- 
2.55.0

Re: [PATCHv3] dt-bindings: mtd: convert IBM NDFC binding to YAML

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dt-bindings: mtd: ibm,ndfc schema rejects modern partitions
--

commit f1a26fcb68368a1ab8dd195e7a927c46335d8315
Author: Rosen Penev <rosenp@gmail.com>

dt-bindings: mtd: convert IBM NDFC binding to YAML

The NDFC NAND flash controller was only described in a legacy text file,
so dtbs_check reported "failed to match any schema". This commit converts
the binding to the YAML format.

> diff --git a/Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml b/Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml
> new file mode 100644
> index 0000000000000..e614c5855b423
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/ibm,ndfc.yaml
[ ... ]
> +  bank-settings:
> +    description: NDFC bank configuration register value.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  nand:
> +    type: object
> +    description: NAND chip attached to the controller.
> +
> +    properties:
> +      "#address-cells":
> +        const: 1
> +      "#size-cells":
> +        const: 1
> +
> +    patternProperties:
> +      "^partition@[0-9a-f]+$":
> +        $ref: /schemas/mtd/partitions/partition.yaml#/$defs/partition-node
> +        deprecated: true
> +
> +    unevaluatedProperties: false

[Severity: Medium]
Does this strict definition of the nand child node prevent device trees from
using modern partition layouts?

Because unevaluatedProperties is set to false without a reference to
/schemas/mtd/mtd.yaml# or /schemas/mtd/nand-chip.yaml#, the schema will
reject modern generic MTD properties.

For example, if a device tree author updates their DTS files by replacing
deprecated direct partition@ nodes with the modern partitions subnode (using
compatible = "fixed-partitions"), dt_binding_check will fail.

Additionally, the node name nand (without a unit address) does not match the
^nand@[a-f0-9]$ regex in the inherited nand-controller-legacy.yaml.

Could this be updated to allow the correct modern alternatives?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260924212240.81857-1-rosenp@gmail.com?part=1