/ {
    model = "JW Kernel Board V1";
    compatible = "jw,kernel-board-v1", "rockchip,rv1106";

    vcc_1v8: vcc-1v8 {
        compatible = "regulator-fixed";
        regulator-name = "vcc_1v8";
        regulator-always-on;
        regulator-boot-on;
        regulator-min-microvolt = <1800000>;
        regulator-max-microvolt = <1800000>;
    };

    vcc_3v3: vcc-3v3 {
        compatible = "regulator-fixed";
        regulator-name = "vcc_3v3";
        regulator-always-on;
        regulator-boot-on;
        regulator-min-microvolt = <3300000>;
        regulator-max-microvolt = <3300000>;
    };
    vcc5v0_usb: vcc5v0-usb {
		compatible = "regulator-fixed";
		regulator-name = "vcc5v0_usb";
		regulator-min-microvolt = <5000000>;
		regulator-max-microvolt = <5000000>;
		enable-active-high;
		gpio = <&gpio0 RK_PA2 GPIO_ACTIVE_HIGH>;
		pinctrl-names = "default";
		pinctrl-0 = <&usb_pwren>;
	};
};
写法实际控制硬件？干什么用
regulator-fixed 无 gpio❌ 不控制就是个标签，告诉内核"这个电压存在"
regulator-fixed 有 gpio✅ 控制一个 GPIO打开/关闭某个电源芯片的使能脚
pwm-regulator✅ 控制 PWM通过 PWM 占空比调压（CPU 核心电压）

cc_1v8 和 vcc_3v3——它们没有 gpio，不控制任何硬件，纯属为了让依赖的驱动能 probe 通过

vcc5v0_usb 它有一个 GPIO 脚去开 USB 口的 5V 供电。