dt-bindings: pinctrl: Add starfive,jhb100-sys2-pinctrl

Add pinctrl bindings for StarFive JHB100 SoC System-2(sys2) pinctrl
controller.

Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>

Documentation/devicetree/bindings/pinctrl/starfive,jhb100-sys2-pinctrl.yaml

@@ -0,0 +1,165 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/starfive,jhb100-sys2-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: StarFive JHB100 System-2 Pin Controller
+
+description: |
+  Pinctrl bindings for JHB100 RISC-V SoC from StarFive Technology Ltd.
+
+  The JHB100 SoC has 13 pinctrl domains - sys0, sys0h, sys1, sys2, per0, per1,
+  per2, per2pok, per3, adc0, adc1, emmc, and vga.
+  This document provides an overview of the "sys2" pinctrl domain.
+
+  The "sys2" domain has a pin controller which provides
+  - function selection for GPIO pads.
+  - GPIO pad configuration.
+  - GPIO interrupt handling.
+
+  In the SYS2 Pin Controller, there are 37 multi-function GPIO_PADs. Each of
+  them can be multiplexed to different hardware blocks through function
+  selection. Each iopad has a maximum of up to 4 functions - 0, 1, 2, and 3.
+  Function 0 is the default function which is the GPIO function.
+  Function 1, 2, and 3 are the alternate functions or peripheral signals that
+  can be routed to the iopad. The function selection can be carried out by
+  writing the function number to the iopad function select register.
+
+  Each iopad is configurable with parameters such as input-enable, internal
+  pull-up/pull-down bias, drive strength, schmitt trigger, slew rate, input
+  debounce nanoseconds, power source.
+
+maintainers:
+  - Changhuang Liang <changhuang.liang@starfivetech.com>
+
+properties:
+  compatible:
+    items:
+      - const: starfive,jhb100-sys2-pinctrl
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  gpio-ranges: true
+
+  gpio-line-names: true
+
+patternProperties:
+  '-grp$':
+    type: object
+    additionalProperties: false
+    patternProperties:
+      '-pins$':
+        type: object
+        description: |
+          A pinctrl node should contain at least one subnode representing the
+          pinctrl groups available in the domain. Each subnode will list the
+          pins it needs, and how they should be configured, with regard to
+          function selection, bias, input enable/disable, input schmitt
+          trigger enable/disable, slew-rate, input debounce nanoseconds,
+          power-source and drive-strength.
+        allOf:
+          - $ref: /schemas/pinctrl/pincfg-node.yaml
+          - $ref: /schemas/pinctrl/pinmux-node.yaml
+        additionalProperties: false
+
+        properties:
+          pins:
+            description:
+              The list of IOs that properties in the pincfg node apply to.
+
+          function:
+            description:
+              A string containing the name of the function to mux for these
+              pins.
+            enum: [ gpio, host0_port80, host1_port80, jtag, smbalert, uart ]
+
+          bias-disable: true
+
+          bias-pull-down:
+            type: boolean
+
+          bias-pull-up:
+            type: boolean
+
+          drive-strength:
+            enum: [ 2, 4, 8, 12 ]
+
+          drive-strength-microamp:
+            enum: [ 2000, 4000, 8000, 12000 ]
+
+          input-debounce-ns:
+            minimum: 0
+            maximum: 10485680
+            description:
+              Debounce time in nanoseconds. The hardware counts in 80 ns
+              stages with a 17-bit counter, so the maximum is 10485680 ns.
+
+          input-disable: true
+
+          input-enable: true
+
+          input-schmitt-enable: true
+
+          input-schmitt-disable: true
+
+          power-source:
+            enum: [ 1800, 3300 ]
+            description: I/O voltage in millivolt.
+
+          slew-rate:
+            enum: [ 0, 1 ]
+            default: 0
+            description: |
+                0: slow
+                1: fast
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+  - '#interrupt-cells'
+  - gpio-controller
+  - '#gpio-cells'
+  - gpio-ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        pinctrl_sys2: pinctrl@13082000 {
+            compatible = "starfive,jhb100-sys2-pinctrl";
+            reg = <0x0 0x13082000 0x0 0x1000>;
+            interrupts = <59>;
+            interrupt-controller;
+            #interrupt-cells = <2>;
+            gpio-controller;
+            #gpio-cells = <2>;
+            gpio-ranges = <&pinctrl_sys2 0 0 37>;
+        };
+    };