How to access gpio-line-names specified in overlay.

Question

Hi all.

I'm trying to learn a bit more about the device overlays,

I'd like to know how I would access the "gpio-line-names" that I've specified in my overlay in my application.

ie when I set or read the I/O point it would be nice to retrieve the friendly gpio-line-name and display it in the log.

	//https://docs.zephyrproject.org/3.0.0/reference/peripherals/gpio.html#c.gpio_port_value_t
	//https://docs.zephyrproject.org/3.0.0/reference/devicetree/bindings/gpio/nxp%2Cpca95xx.html#dtbinding-nxp-pca95xx
	pca95xx_feather0: pca95xx@74 {		//we might have more than one feather expansion		
		status = "okay";
		compatible = "nxp,pca95xx";
		#gpio-cells = <2>;
		gpio-controller;
		reg = <0x74>;
		ngpios = < 16 >;
		interrupt-gpios = < &gpio0 25 GPIO_ACTIVE_LOW>;
		gpio-line-names = "di0","di1","di2","di3",   "do0","do1","do2","do3",  "wdt_wake","wdt_done","load_dis",  "led_blu","led_red","led_yel","led_grn";
	};

Regards

Marshall

Marshall · Accepted Answer

You do it like this. 
 
 #define BASE_EXPANDER DT_NODELABEL(pca95xx_feather0)
#if DT_NODE_HAS_STATUS(BASE_EXPANDER,okay)
	const struct device *const gpio_expander = DEVICE_DT_GET(BASE_EXPANDER);
	const char *useful_gpio_names[] = DT_PROP(BASE_EXPANDER,gpio_line_names);

#else 
	#error "pca95xx_feather0 device is disabled."	
#endif