dt-bindings: add BCM6328 pincontroller binding documentation

Add binding documentation for the pincontrol core found in BCM6328 SoCs.
Co-developed-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210324081923.20379-6-noltari@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/brcm,bcm6328-pinctrl.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/brcm,bcm6328-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM6328 pin controller
+
+maintainers:
+  - Álvaro Fernández Rojas <noltari@gmail.com>
+  - Jonas Gorski <jonas.gorski@gmail.com>
+
+description:
+  Bindings for Broadcom's BCM6328 memory-mapped pin controller.
+
+properties:
+  compatible:
+    const: brcm,bcm6328-pinctrl
+
+  reg:
+    maxItems: 1
+
+patternProperties:
+  '-pins$':
+    type: object
+    $ref: pinmux-node.yaml#
+
+    properties:
+      function:
+        enum: [ serial_led_data, serial_led_clk, inet_act_led, pcie_clkreq,
+                led, ephy0_act_led, ephy1_act_led, ephy2_act_led,
+                ephy3_act_led, hsspi_cs1, usb_device_port, usb_host_port ]
+
+      pins:
+        enum: [ gpio6, gpio7, gpio11, gpio16, gpio17, gpio18, gpio19,
+                gpio20, gpio25, gpio26, gpio27, gpio28, hsspi_cs1,
+                usb_port1 ]
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    pinctrl@18 {
+      compatible = "brcm,bcm6328-pinctrl";
+      reg = <0x18 0x10>;
+
+      pinctrl_serial_led: serial_led-pins {
+        pinctrl_serial_led_data: serial_led_data-pins {
+          function = "serial_led_data";
+          pins = "gpio6";
+        };
+
+        pinctrl_serial_led_clk: serial_led_clk-pins {
+          function = "serial_led_clk";
+          pins = "gpio7";
+        };
+      };
+
+      pinctrl_inet_act_led: inet_act_led-pins {
+        function = "inet_act_led";
+        pins = "gpio11";
+      };
+
+      pinctrl_pcie_clkreq: pcie_clkreq-pins {
+        function = "pcie_clkreq";
+        pins = "gpio16";
+      };
+
+      pinctrl_ephy0_spd_led: ephy0_spd_led-pins {
+        function = "led";
+        pins = "gpio17";
+      };
+
+      pinctrl_ephy1_spd_led: ephy1_spd_led-pins {
+        function = "led";
+        pins = "gpio18";
+      };
+
+      pinctrl_ephy2_spd_led: ephy2_spd_led-pins {
+        function = "led";
+        pins = "gpio19";
+      };
+
+      pinctrl_ephy3_spd_led: ephy3_spd_led-pins {
+        function = "led";
+        pins = "gpio20";
+      };
+
+      pinctrl_ephy0_act_led: ephy0_act_led-pins {
+        function = "ephy0_act_led";
+        pins = "gpio25";
+      };
+
+      pinctrl_ephy1_act_led: ephy1_act_led-pins {
+        function = "ephy1_act_led";
+        pins = "gpio26";
+      };
+
+      pinctrl_ephy2_act_led: ephy2_act_led-pins {
+        function = "ephy2_act_led";
+        pins = "gpio27";
+      };
+
+      pinctrl_ephy3_act_led: ephy3_act_led-pins {
+        function = "ephy3_act_led";
+        pins = "gpio28";
+      };
+
+      pinctrl_hsspi_cs1: hsspi_cs1-pins {
+        function = "hsspi_cs1";
+        pins = "hsspi_cs1";
+      };
+
+      pinctrl_usb_port1_device: usb_port1_device-pins {
+        function = "usb_device_port";
+        pins = "usb_port1";
+      };
+
+      pinctrl_usb_port1_host: usb_port1_host-pins {
+        function = "usb_host_port";
+        pins = "usb_port1";
+      };
+    };