Functional GPIO

The following code blocks show an example of a functional GPIO device tree configuration.

        pcie0_perst_default: pcie0_perst_default {
                perst-pins {
                        sf,pins = <PAD_GPIO26>;
                        sf,pinmux = <PAD_GPIO26_FUNC_SEL 0>;
                        sf,pin-ioconfig = <IO(GPIO_IE(1))>;
                        sf,pin-gpio-dout = <GPO_HIGH>;
                        sf,pin-gpio-doen = <OEN_LOW>;
                };
        };

        pcie0_perst_active: pcie0_perst_active {
                perst-pins {
                        sf,pins = <PAD_GPIO26>;
                        sf,pinmux = <PAD_GPIO26_FUNC_SEL 0>;
                        sf,pin-ioconfig = <IO(GPIO_IE(1))>;
                        sf,pin-gpio-dout = <GPO_LOW>;
                        sf,pin-gpio-doen = <OEN_LOW>;
                };
        };

        pcie0_power_active: pcie0_power_active {
                power-pins {
                        sf,pins = <PAD_GPIO32>;
                        sf,pinmux = <PAD_GPIO32_FUNC_SEL 0>;
                        sf,pin-ioconfig = <IO(GPIO_IE(1))>;
                        sf,pin-gpio-dout = <GPO_HIGH>;
                        sf,pin-gpio-doen = <OEN_LOW>;
                };
        };

&pcie0 {
        pinctrl-names = "perst-default", "perst-active", "power-active";
        pinctrl-0 = <&pcie0_perst_default>;
        pinctrl-1 = <&pcie0_perst_active>;
        pinctrl-2 = <&pcie0_power_active>;
        status = "okay";
};

In the above example, make sure you understand the use of the following values:

• The parameter value of “perst-default” in pinctrl-0 is the pin configuration for normal work mode.
• The parameter value of “perst-active” in pinctrl-1 is the pin configuration for active mode.