[PATCH v4] dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema

[PATCH v4] dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema

[Udaya Kiran Challa]

Convert Microchip PIC32 Pin Controller devicetree binding
from legacy text format to DT schema.

Signed-off-by: Udaya Kiran Challa <challauday369@gmail.com>
---
Changelog:
Changes since v3:
- Drop "|" from description fields
- Remove '#address-cells' and '#size-cells' properties from the schema
- Consolidate repeated pin-node property definitions into a single
  $defs/pin-node entry
- Replace the two patternProperties blocks with additionalProperties
  using oneOf to allow either:
  - container nodes holding nested pin configuration nodes, or
  - direct pin configuration nodes.
- Update $ref to use the absolute schema path
  /schemas/pinctrl/pinmux-node.yaml#

Link to v3:https://lore.kernel.org/all/20260719183431.124061-1-challauday369@gmail.com/

Changes since v2:
- Add container node for grouped pin configuration sub-nodes
- Correct regex patterns of direct and nested child nodes
- Fix interrupts values in uart2 example

Link to v2:https://lore.kernel.org/all/20260707144223.120417-1-challauday369@gmail.com/

Changes since v1:
- Add interrupts and clocks to uart2 example to satisfy uart schema validation
- Corect regex patterns to accept standard DT node naming conventions
- Add function property to top-level pin configuration nodes
- Remove restrictive enum from function property to support all mux functions

Link to v1:https://lore.kernel.org/all/20260705132521.159522-1-challauday369@gmail.com/
---
 .../pinctrl/microchip,pic32-pinctrl.txt       |  60 ----------
 .../pinctrl/microchip,pic32mzda-pinctrl.yaml  | 107 ++++++++++++++++++
 2 files changed, 107 insertions(+), 60 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/pinctrl/microchip,pic32-pinctrl.txt
 create mode 100644 Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml

diff --git a/Documentation/devicetree/bindings/pinctrl/microchip,pic32-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/microchip,pic32-pinctrl.txt
deleted file mode 100644
index 51efd2085113..000000000000
--- a/Documentation/devicetree/bindings/pinctrl/microchip,pic32-pinctrl.txt
+++ /dev/null
@@ -1,60 +0,0 @@
-* Microchip PIC32 Pin Controller
-
-Please refer to pinctrl-bindings.txt, ../gpio/gpio.txt, and
-../interrupt-controller/interrupts.txt for generic information regarding
-pin controller, GPIO, and interrupt bindings.
-
-PIC32 'pin configuration node' is a node of a group of pins which can be
-used for a specific device or function. This node represents configurations of
-pins, optional function, and optional mux related configuration.
-
-Required properties for pin controller node:
- - compatible: "microchip,pic32mada-pinctrl"
- - reg: Address range of the pinctrl registers.
- - clocks: Clock specifier (see clock bindings for details)
-
-Required properties for pin configuration sub-nodes:
- - pins: List of pins to which the configuration applies.
-
-Optional properties for pin configuration sub-nodes:
-----------------------------------------------------
- - function: Mux function for the specified pins.
- - bias-pull-up: Enable weak pull-up.
- - bias-pull-down: Enable weak pull-down.
- - input-enable: Set the pin as an input.
- - output-low: Set the pin as an output level low.
- - output-high: Set the pin as an output level high.
- - microchip,digital: Enable digital I/O.
- - microchip,analog: Enable analog I/O.
-
-Example:
-
-pic32_pinctrl: pinctrl@1f801400{
-	#address-cells = <1>;
-	#size-cells = <1>;
-	compatible = "microchip,pic32mzda-pinctrl";
-	reg = <0x1f801400 0x400>;
-	clocks = <&rootclk PB1CLK>;
-
-	pinctrl_uart2: pinctrl_uart2 {
-		uart2-tx {
-			pins = "G9";
-			function = "U2TX";
-			microchip,digital;
-			output-low;
-		};
-		uart2-rx {
-			pins = "B0";
-			function = "U2RX";
-			microchip,digital;
-			input-enable;
-		};
-	};
-};
-
-uart2: serial@1f822200 {
-	compatible = "microchip,pic32mzda-uart";
-	reg = <0x1f822200 0x50>;
-	pinctrl-names = "default";
-	pinctrl-0 = <&pinctrl_uart2>;
-};
diff --git a/Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml
new file mode 100644
index 000000000000..a1ecae3b1cd8
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml
@@ -0,0 +1,107 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/microchip,pic32mzda-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PIC32 Pin Controller
+
+maintainers:
+  - Linus Walleij <linusw@kernel.org>
+
+description:
+  PIC32 pin configuration node is a node of a group of pins which can be used
+  for a specific device or function. This node represents configurations of
+  pins, optional function, and optional mux related configuration.
+
+properties:
+  compatible:
+    const: microchip,pic32mzda-pinctrl
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+$defs:
+  pin-node:
+    type: object
+    $ref: /schemas/pinctrl/pinmux-node.yaml#
+
+    properties:
+      pins:
+        description: List of pins to which the configuration applies.
+        items:
+          type: string
+        minItems: 1
+
+      function: true
+
+      bias-pull-up: true
+      bias-pull-down: true
+      input-enable: true
+      output-low: true
+      output-high: true
+
+      microchip,digital:
+        description: Enable digital I/O.
+        type: boolean
+
+      microchip,analog:
+        description: Enable analog I/O.
+        type: boolean
+
+    required:
+      - pins
+
+    unevaluatedProperties: false
+
+additionalProperties:
+  oneOf:
+    - additionalProperties:
+        $ref: '#/$defs/pin-node'
+    - $ref: '#/$defs/pin-node'
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+examples:
+  - |
+    #include <dt-bindings/clock/microchip,pic32-clock.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    pic32_pinctrl: pinctrl@1f801400 {
+        compatible = "microchip,pic32mzda-pinctrl";
+        reg = <0x1f801400 0x400>;
+        clocks = <&rootclk PB1CLK>;
+
+        pinctrl_uart2: pinctrl_uart2 {
+            uart2-tx {
+                pins = "G9";
+                function = "U2TX";
+                microchip,digital;
+                output-low;
+            };
+
+            uart2-rx {
+                pins = "B0";
+                function = "U2RX";
+                microchip,digital;
+                input-enable;
+            };
+        };
+    };
+
+    uart2: serial@1f822200 {
+        compatible = "microchip,pic32mzda-uart";
+        reg = <0x1f822200 0x50>;
+        interrupts = <145 IRQ_TYPE_LEVEL_HIGH>,
+                     <146 IRQ_TYPE_LEVEL_HIGH>,
+                     <147 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&rootclk PB2CLK>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&pinctrl_uart2>;
+    };
-- 
2.34.1

Re: [PATCH v4] dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [High] The top-level `additionalProperties` logic using `oneOf` silently accepts undefined non-object properties and breaks validation for standard container nodes due to injected `phandle` properties.
- [Medium] The `$defs/pin-node` definition bypasses all type and constraint checking for standard pin configuration properties because it fails to reference `pincfg-node.yaml`.
- [Low] The removal of `#address-cells` and `#size-cells` from the schema creates a mismatch with the existing `pic32mzda.dtsi`, which will cause `dtbs_check` warnings.
--

--- Patch [1]: [PATCH v4] dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema ---
commit 238b9bfa23edd44c05fbb35e962f0ab9f0bb9f25
Author: Udaya Kiran Challa <challauday369@gmail.com>
Date:   Wed Jul 22 12:32:43 2026 +0000

dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema
    
This commit converts the Microchip PIC32 Pin Controller devicetree binding
from legacy text format to DT schema. It consolidates pin-node properties and
updates the schema layout to support nested or direct pin configurations.

Link to v3: https://lore.kernel.org/all/20260719183431.124061-1-challauday369@gmail.com/
Link to v2: https://lore.kernel.org/all/20260707144223.120417-1-challauday369@gmail.com/
Link to v1: https://lore.kernel.org/all/20260705132521.159522-1-challauday369@gmail.com/

> diff --git a/Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/microchip,pic32mzda-pinctrl.yaml
> @@ -0,0 +1,107 @@
[ ... ]
> +properties:
> +  compatible:
> +    const: microchip,pic32mzda-pinctrl
> +
> +  reg:
> +    maxItems: 1

[Severity: Low]
Even though the changelog mentions removing #address-cells and #size-cells
from the schema, aren't these properties still present in the
pinctrl@1f801400 node in arch/mips/boot/dts/pic32/pic32mzda.dtsi? 

Will their removal from the schema cause dtbs_check warnings for the
existing in-tree device tree?

> +
> +  clocks:
> +    maxItems: 1
> +
> +$defs:
> +  pin-node:
> +    type: object
> +    $ref: /schemas/pinctrl/pinmux-node.yaml#
> +
> +    properties:
> +      pins:
> +        description: List of pins to which the configuration applies.
> +        items:
> +          type: string
> +        minItems: 1
> +
> +      function: true
> +
> +      bias-pull-up: true
> +      bias-pull-down: true
> +      input-enable: true
> +      output-low: true
> +      output-high: true

[Severity: Medium]
Does this bypass type and constraint checking for the generic pin
configuration properties?

By assigning these generic properties to true without also including a
$ref: /schemas/pinctrl/pincfg-node.yaml#, it looks like the schema
validator might silently accept any value or type for them, missing
mutually exclusive constraints like having both output-low and
output-high present.

> +
> +      microchip,digital:
> +        description: Enable digital I/O.
> +        type: boolean
> +
[ ... ]
> +    required:
> +      - pins
> +
> +    unevaluatedProperties: false
> +
> +additionalProperties:
> +  oneOf:
> +    - additionalProperties:
> +        $ref: '#/$defs/pin-node'
> +    - $ref: '#/$defs/pin-node'

[Severity: High]
Will this oneOf construct silently accept undefined scalar properties?

Because the first branch lacks a type: object constraint, a typoed
scalar property might trivially pass the first branch and satisfy the
oneOf.

Also, for valid child container nodes referenced via a phandle, the
devicetree compiler automatically injects a phandle property. Since
that injected phandle is not an object, won't it fail the $ref type
check here and cause spurious dtbs_check errors for perfectly valid
hardware configurations?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722123243.341346-1-challauday369@gmail.com?part=1