dt-bindings: pinctrl: Add support for canaan,k230 SoC

Add device tree binding details for Canaan K230 pinctrl device.

Signed-off-by: Ze Huang <18771902331@163.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/20240926-k230-pinctrl-v2-1-a9a36fba4b34@163.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/canaan,k230-pinctrl.yaml

@@ -0,0 +1,127 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/canaan,k230-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Canaan Kendryte K230 Pin Controller
+
+maintainers:
+  - Ze Huang <18771902331@163.com>
+
+description:
+  The Canaan Kendryte K230 platform includes 64 IO pins, each capable of
+  multiplexing up to 5 different functions. Pin function configuration is
+  performed on a per-pin basis.
+
+properties:
+  compatible:
+    const: canaan,k230-pinctrl
+
+  reg:
+    maxItems: 1
+
+patternProperties:
+  '-pins$':
+    type: object
+    additionalProperties: false
+    description:
+      A pinctrl node should contain at least one subnode representing the
+      pinctrl groups available on the machine.
+
+    patternProperties:
+      '-cfg$':
+        type: object
+        allOf:
+          - $ref: /schemas/pinctrl/pincfg-node.yaml
+          - $ref: /schemas/pinctrl/pinmux-node.yaml
+        additionalProperties: false
+        description:
+          Each subnode will list the pins it needs, and how they should
+          be configured, with regard to muxer configuration, bias, input
+          enable/disable, input schmitt trigger, slew-rate enable/disable,
+          slew-rate, drive strength.
+
+        properties:
+          pinmux:
+            description:
+              The list of GPIOs and their mux settings that properties in
+              the node apply to. This should be set with the macro
+              'K230_PINMUX(pin, mode)'
+
+          bias-disable: true
+
+          bias-pull-up: true
+
+          bias-pull-down: true
+
+          drive-strength:
+            minimum: 0
+            maximum: 15
+
+          input-enable: true
+
+          output-enable: true
+
+          input-schmitt-enable: true
+
+          slew-rate:
+            description: |
+              slew rate control enable
+              0: disable
+              1: enable
+
+            enum: [0, 1]
+
+          power-source:
+            description: |
+              Specifies the power source voltage for the IO bank that the
+              pin belongs to. Each bank of IO pins operate at a specific,
+              fixed voltage levels. Incorrect voltage configuration can
+              damage the chip. The defined constants represent the
+              possible voltage configurations:
+
+              - K230_MSC_3V3 (value 0): 3.3V power supply
+              - K230_MSC_1V8 (value 1): 1.8V power supply
+
+              The following banks have the corresponding voltage
+              configurations:
+
+              - bank IO0 to IO1: Fixed at 1.8V
+              - bank IO2 to IO13: Fixed at 1.8V
+              - bank IO14 to IO25: Fixed at 1.8V
+              - bank IO26 to IO37: Fixed at 1.8V
+              - bank IO38 to IO49: Fixed at 1.8V
+              - bank IO50 to IO61: Fixed at 3.3V
+              - bank IO62 to IO63: Fixed at 1.8V
+
+            enum: [0, 1]
+
+        required:
+          - pinmux
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    pinctrl@91105000 {
+        compatible = "canaan,k230-pinctrl";
+        reg = <0x91105000 0x100>;
+
+        uart2-pins {
+            uart2-pins-cfg {
+                pinmux = <0x503>, /* uart2 txd */
+                         <0x603>; /* uart2 rxd */
+                slew-rate = <0>;
+                drive-strength = <4>;
+                power-source = <1>;
+                input-enable;
+                output-enable;
+                bias-disable;
+            };
+        };
+    };