dt-bindings: pinctrl: Add support for Amlogic A4 SoC

Add the dt-bindings for Amlogic pin controller, and add a new
dt-binding header file which document the GPIO bank names of
Amlogic A4 SoC.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/20250212-amlogic-pinctrl-v5-1-282bc2516804@amlogic.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/amlogic,pinctrl-a4.yaml

@@ -0,0 +1,126 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/amlogic,pinctrl-a4.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic pinmux controller
+
+maintainers:
+  - Xianwei Zhao <xianwei.zhao@amlogic.com>
+
+allOf:
+  - $ref: pinctrl.yaml#
+
+properties:
+  compatible:
+    const: amlogic,pinctrl-a4
+
+  "#address-cells":
+    const: 2
+
+  "#size-cells":
+    const: 2
+
+  ranges: true
+
+patternProperties:
+  "^gpio@[0-9a-f]+$":
+    type: object
+
+    additionalProperties: false
+    properties:
+      reg:
+        minItems: 1
+        items:
+          - description: pin config register
+          - description: pin mux setting register (some special pin fixed function)
+          - description: pin drive strength register (optional)
+
+      reg-names:
+        minItems: 1
+        items:
+          - const: gpio
+          - const: mux
+          - const: ds
+
+      gpio-controller: true
+
+      "#gpio-cells":
+        const: 2
+
+      gpio-ranges:
+        maxItems: 1
+
+    required:
+      - reg
+      - reg-names
+      - gpio-controller
+      - "#gpio-cells"
+      - gpio-ranges
+
+  "^func-[0-9a-z-]+$":
+    type: object
+    additionalProperties: false
+    patternProperties:
+      "^group-[0-9a-z-]+$":
+        type: object
+        allOf:
+          - $ref: /schemas/pinctrl/pincfg-node.yaml
+          - $ref: /schemas/pinctrl/pinmux-node.yaml
+
+        required:
+          - pinmux
+
+required:
+  - compatible
+  - "#address-cells"
+  - "#size-cells"
+  - ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/pinctrl/amlogic,pinctrl.h>
+    apb {
+      #address-cells = <2>;
+      #size-cells = <2>;
+      periphs_pinctrl: pinctrl {
+        compatible = "amlogic,pinctrl-a4";
+        #address-cells = <2>;
+        #size-cells = <2>;
+        ranges;
+
+        gpio@4240 {
+          reg = <0 0x4240 0 0x40>, <0 0x4000 0 0x8>;
+          reg-names = "gpio", "mux";
+          gpio-controller;
+          #gpio-cells = <2>;
+          gpio-ranges = <&periphs_pinctrl 0 8 10>;
+        };
+
+        func-uart-b {
+          group-default {
+            pinmux = <AML_PINMUX(AMLOGIC_GPIO_B, 1, 4)>;
+            bias-pull-up;
+            drive-strength-microamp = <4000>;
+          };
+
+          group-pins1 {
+            pinmux = <AML_PINMUX(AMLOGIC_GPIO_B, 5, 2)>;
+            bias-pull-up;
+            drive-strength-microamp = <4000>;
+          };
+        };
+
+        func-uart-c {
+          group-default {
+            pinmux = <AML_PINMUX(AMLOGIC_GPIO_B, 3, 1)>,
+                     <AML_PINMUX(AMLOGIC_GPIO_B, 2, 1)>;
+            bias-pull-up;
+            drive-strength-microamp = <4000>;
+          };
+        };
+      };
+    };

include/dt-bindings/pinctrl/amlogic,pinctrl.h

@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR MIT) */
+/*
+ * Copyright (c) 2024 Amlogic, Inc. All rights reserved.
+ * Author: Xianwei Zhao <xianwei.zhao@amlogic.com>
+ */
+
+#ifndef _DT_BINDINGS_AMLOGIC_PINCTRL_H
+#define _DT_BINDINGS_AMLOGIC_PINCTRL_H
+/* Normal PIN bank */
+#define AMLOGIC_GPIO_A		0
+#define AMLOGIC_GPIO_B		1
+#define AMLOGIC_GPIO_C		2
+#define AMLOGIC_GPIO_D		3
+#define AMLOGIC_GPIO_E		4
+#define AMLOGIC_GPIO_F		5
+#define AMLOGIC_GPIO_G		6
+#define AMLOGIC_GPIO_H		7
+#define AMLOGIC_GPIO_I		8
+#define AMLOGIC_GPIO_J		9
+#define AMLOGIC_GPIO_K		10
+#define AMLOGIC_GPIO_L		11
+#define AMLOGIC_GPIO_M		12
+#define AMLOGIC_GPIO_N		13
+#define AMLOGIC_GPIO_O		14
+#define AMLOGIC_GPIO_P		15
+#define AMLOGIC_GPIO_Q		16
+#define AMLOGIC_GPIO_R		17
+#define AMLOGIC_GPIO_S		18
+#define AMLOGIC_GPIO_T		19
+#define AMLOGIC_GPIO_U		20
+#define AMLOGIC_GPIO_V		21
+#define AMLOGIC_GPIO_W		22
+#define AMLOGIC_GPIO_X		23
+#define AMLOGIC_GPIO_Y		24
+#define AMLOGIC_GPIO_Z		25
+
+/* Special PIN bank */
+#define AMLOGIC_GPIO_DV		26
+#define AMLOGIC_GPIO_AO		27
+#define AMLOGIC_GPIO_CC		28
+#define AMLOGIC_GPIO_TEST_N	29
+#define AMLOGIC_GPIO_ANALOG	30
+
+#define AML_PINMUX(bank, offset, mode)	(((((bank) << 8) + (offset)) << 8) | (mode))
+
+#endif /* _DT_BINDINGS_AMLOGIC_PINCTRL_H */